Technical ReportPDF Available

Climate change impacts on biodiversity in coastal and marine environments of Caribbean Small Island Developing States (SIDs)

January 2017

January 2017

Report number: Science review 2017
Affiliation: Centre for Environment, Fisheries and Aquaculture Science

Authors:

ERM Consultancy

• The current and future available evidence (based on AR5 scenarios) suggests that small islands will be vulnerable to sea level rise (SLR), increased sea surface temperature (SST) and decreased extent of coastal vegetated wetlands; • The impact of increased SST on seagrass beds in the Caribbean is uncertain, but recent evidence suggests that the photosynthetic mechanism of tropical seagrasses could become damaged at temperatures of 40-45°C; • Coral bleaching could become an annual or biannual event in the next 30 to 50 years or sooner, without an increase in thermal tolerance of 0.2 to 1.0°C; • In the Caribbean, there is a 0.5 m SLR projected which is likely to cause a decrease in turtle nesting habitat by up to 35%; • Recent research has shown that the invasion of the Caribbean Sea by the successful predator the Indo-Pacific lionfish (Pterois volitans) has contributed to an increase in algal dominance in coral and sponge communities in the Caribbean region. Presence of the predator may reduce the resilience of reef communities to climate stressors, and vice versa.

Overview of the maritime area of the Small Island Developing States (SIDS) in the Caribbean.

…

Figures - uploaded by Silvana NR Birchenough

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Content uploaded by Silvana NR Birchenough

Content may be subject to copyright.

CARIBBEAN MARINE CLIMATE CHANGE REPORT CARD: SCIENCE REVIEW 2017

Science Review 2017: pp 40-51.

Impacts of Climate Change on Biodiversity in the Coastal and

Marine Environments of Caribbean Small Island Developing States

(SIDS)

Silvana N.R. Birchenough

Cefas Marine Climate Change Centre. The Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft,

NR33 0HT, UK.

Introduction

The Caribbean region has been recognised to be a hot-spot for

biodiversity worldwide (UNEP, 2009; Myers et al., 2000). This

report card summarises the current evidence and expected

future climate change effects on important marine habitats and

species. The topics considered in this review are seagrasses

and turtles, mammals, plankton and invasive species. Whilst it

is acknowledged that other habitats and species are also

contributing towards the overall biodiversity (e.g. coral, fish and

shellfish, and mangroves) in these areas, these habitats and

species have been covered as individual (‘hot topic’) reports.

However, this review has also included a brief section where

these important species and habitats have been considered

because they are key contributors to the overall Caribbean

biodiversity. In this short summary, we have indicated the likely

expected climate change effects. The observed effects of

climate change and expected future changes will act differently

across species and habitats. Some SIDS are already

experiencing some of these changes and in some cases there

will be some site-specific effects across these areas.

This review has collated information on all countries in the

Caribbean Region, however, the main emphasis is on the

following Small Island Development States (SIDS): Antigua &

EXECUTIVE SUMMARY

The current and future available evidence (based on AR5 scenarios) suggests that small islands will be vulnerable to sea

level rise (SLR) and increased sea surface temperature (SST). Extent of coastal vegetated wetlands is also expected to

decrease;

The impact of increased SST on seagrass and mangroves beds in the Caribbean is uncertain, but some studies suggests

that the photosynthetic mechanism of tropical seagrasses could become damaged at very high temperatures;

Shellfish and fisheries are important food and economic resources for SIDS. These may be directly and indirectly affected

under climate change effects, further research is needed to fully understand and minimise these expected effects;

Some evidence suggests that increased temperatures and low winds could be favouring the appearance of Sargassum

natans and Sargassum fluitans introduction in the Caribbean region;

Coral bleaching could become an annual or biannual event in the next 30 to 50 years or sooner, without an increase in

thermal tolerance of corals of 0.2 to 1.0°C;

In the Caribbean, there is a 0.5 m SLR projected which is likely to cause a decrease in turtle nesting habitat by up to 35%;

Recent research has shown that the invasion of the Caribbean Sea by the successful predator the Indo-Pacific lionfish

(Pterois volitans) has contributed to an increase in algal dominance in coral and sponge communities in the Caribbean

region. Presence of the predator may reduce the resilience of reef communities to climate stressors, and vice versa;

Plans and some actions to mitigate the effects of climate change on biodiversity are already being developed in some SIDS,

but this work is still in its infancy.

Barbuda; Belize; Dominica; Grenada; Guyana; Jamaica; Saint

Lucia; Saint Vincent & Grenadines (Figure 1). This section on

key impacts has integrated knowledge on i) what is already

happening? and ii) what could happen in the future? A detailed

overview is provided on seagrasses and specific species. It is

expected that the effects of climate change on biodiversity will

have synergistic interactions with other human activities (e.g.

fishing, recreational sports, tourisms, sewage discharges) and

will have repercussions for the ecology and ecosystems

distributed in these areas. Climate change effects may have

interactions with many other stressors as documented

elsewhere (Birchenough et al., 2015; Day 2009).

Figure 1. Overview of the maritime area of the Small Island

Developing States (SIDS) in the Caribbean.

Key topics

Some of the main issues for corals, mangroves, fish and shellfish

key topics are briefly included in the sections below. However, a

dedicated review can be found in the full research papers

concentrating on these topics see (see Wilson, 2017 mangroves;

Oxenford and Monnereau, 2017 -fish and shellfish; McField,

2017 corals). The topic research papers have included sections

on: key messages, what is already happening, what could

happen in the future, the confidence levels based on our current

understanding as well as knowledge gaps and socio-economic

impacts.

What is Already Happening?

Corals

Coral reefs are important habitats as they provide shoreline

protection from extreme events such as storms and hurricanes.

Their role also contributes to the provision of medicines, food,

and recreational activities. Their overall estimated global value

of 172 billion U.S. dollars per year (EurekAlert-AAAS, 2009). A

study assessing Belize’s coral reef and coastal mangroves

estimated their overall value to be $395 - $559 million U.S.

dollars per year, considering all of the direct benefits and wider

ecosystem services (Cooper et al, 2009). Corals also host much

of the biodiversity of the oceans as well as providing critical

protection against erosion and wave-induced damages resulting

from tropical storms and hurricanes, safeguarding properties and

lives. To date, evidence suggests that climate change is

impacting coral reefs through coral bleaching, disease

outbreaks, ocean acidification and dedicated physical damage

from frequent hurricanes. Additionally, an increase in sea

temperature is clearly having an impact on the coral reef

ecosystem health globally (McField, 2017 for further details).

Meta-analyses have indicated that global climate change could

increase the frequency of coral bleaching threating the long-term

integrity of coral reefs. These results were based on the

projecting outputs from an atmosphere–ocean general

circulation models (GCMs), with regards to the local conditions

found across representative coral reefs. The overall work is a

comprehensive global assessment of coral bleaching, based on

the work conducted by the NOAA Coral Reef Watch bleaching

prediction method, with a low- and high-climate sensitivity GCM.

The overall results were site-specific, very dependent of the

geographic variability observed over thermal adaptation.

Research suggest that bleaching could become an annual or

biannual event for the majority of the world's coral reefs in the

next 30–50 years without an increase in thermal tolerance of

0.2–1.0°C per decade. The work conducted was based on

available model and emissions scenarios, suggesting that for

some coral reefs, the expected effects resulting from climate

change will vary across regions (Donner et al., 2005).

Overall, the Caribbean SIDS have not yet experienced the global

widespread degree of bleaching-induced mass mortality

compared effects observed elsewhere (e.g. areas in the Pacific).

However, some clear events have been recently observed in

certain areas (e.g. Belize) (McField, 2017). Furthermore, the

resulting effects on coral integrity resulting from diseases have

been underestimated. Maynard et al. (2016) postulated that

bleaching is the likely cause of coral mortality in the future and

that further consideration needs to be included in management

and monitoring of these areas. The increase in sea temperature

is also contributing to the declines in coral reproductive success

(Baird et al., 2009), metabolic rates (Munday et al., 2009), and

shifts in geo-graphic ranges (Hughes et al., 2012). Overall, the

combined effects of climate change with overfishing and

pollution could exacerbate the effects on coral reefs over recent

decades (Game et al., 2005). There is a need to climate proof

the current conservation strategies to protect, restore and

manage these important habitats.

Mangroves

Mangroves cover approximately 137,760 km2 – 152,360km2 of

the world’s surface (Kainuma et al., 2013), these habitats are

highly threatened worldwide (Spalding et al., 2010). There are

four mangrove species—Rhizophora mangle, Avicennia

germinans, Laguncularia racemose and Conocarpus erectus—

found throughout the Wider Caribbean. Studies show that the

loss of mangroves worldwide has been severe over the last

several decades. Mangrove habitats are important as they

provide numerous ecosystem services for human wellbeing (Van

Bochove et al., 2014; Friess, 2016) and climate change could be

also adding an additional pressure to these species. Mangroves

are important as they enhance coastal fisheries, sequester

carbon, provide provisions to local inhabitants, filter nutrients and

sediment, support tourism and protect coastlines and coastal

communities from waves and storms among other values

(Mukherjee et al., 2014). In the Caribbean, particularly in SIDS,

mangroves provide numerous commercial and subsistence

goods, serve as a natural form of coastal protection and

resilience, and support a range of marine and coastal tourism

enterprises (Brown et al., 2007).

Studies have demonstrated that mangroves across the

Caribbean have declined by approximately 24% over the last

quarter-century (Polidoro et al., 2010). The main human

activities which are considered to be drivers of mangrove

destruction and/or degradation are mainly resulting from land

use activities along the coastal zone (Spalding et al., 2010; Van

Bochove et al, 2014). Studies have listed the primary and

emergent anthropogenic threats to mangroves. These are

outlined below:

• Coastal development (e.g. roads, ports, urban

growth and tourism accommodations)

• Agriculture and aquaculture

• Pollution and environmental degradation

• Local exploitation (e.g. wood for cooking or

building)

• Rising seas due to climate change

The 5th Assessment Report prepared by the Intergovernmental

Panel on Climate Change (IPCC-AR5), contains a section on

small islands. This work indentified main climate and pressures

that are expected to impact mangrove ecosystems in Caribbean

SIDS (Nurse et al., 2014). These include the following:

• Variations in air and ocean temperatures

• Ocean chemistry

• Rainfall

• Wind strength and direction

• Sea levels and wave climate (especially extremes such

as hurricanes, drought and storm surges)

Furthermore, a recent review of climate change impacts on

mangrove ecosystems (Alongi, 2015; McKee 2011 and Krauss

et al., 2013) conducted a comprehensive review of the SLR issue

as these effects are directly related to mangroves (McIvor,

2012). This work showed that the presence of deep peat

deposits, provides evidence that in some Caribbean locations in

the past, landward migration of mangroves continue to shift with

SLR. Additional studies have also shown some limits in which

mangroves cannot keep pace with SLR, demonstrating the

degration of these habitats (Alongi, 2015).

Fish and shellfish

Fish and shellfish are important economic and food resources in

the SIDS. Some of the shellfish and fish are already experiencing

climate change effects. For example, measurements of across

the entire Caribbean Sea have shown an overall increase in

SST; with an increase in the frequency of occurrence of

anomalous ‘hotspots’ (e.g. greater than 1°C above mean

monthly maximum SST), as well as an increase in the

occurrence of periods of deleterious ‘heating stress’ (greater

than 8 degree heating weeks), and an increase in the frequency

of category 4 and 5 hurricanes. It is clear that warmer SSTs are

having a direct impact on Caribbean fish and shellfish

metabolism since they are poikilothermic ectotherms (‘cold

blooded’). This impact is likely to be largely negative, given that

many species are already likely to be close to their critical

maximum temperature and minimum oxygen tolerances, at least

during the summer months. Changing temperatures will have

already impacted species’ phenologies and early life history

development times with the likely result of less successful

recruitment (population replenishment). However, again there

are no studies that have examined likely changes in, for

example: metabolic rate, growth, development of early life

history stages, phenologies, or mortality from anoxia in

Caribbean species from any of the commercially important

groups in the wild, over time-scales long enough to detect

change that can be attributed to climate-induced changes in

SST.

However, increasing SSTs and associated changes have had

measurable negative impacts across the Caribbean on the

essential habitats of fish and shellfish, especially coral reefs

since the 1980s, through mass coral bleaching and mortality

events, increased incidences of coral and other invertebrate

diseases, and greater physical destruction. These climate

change stressors have exacerbated the on-going chronic

degradation of these habitats from other anthropogenic stressors

including deteriorating water quality (from land-based activities

along the coast and within watersheds), physical destruction

(from coastal development and marine construction), and

chronic over-harvesting. The evidence is clear in the changing

composition of the foundational reef species, the decline in live

coral cover and architectural complexity (rugosity) of reef

structural framework; as well as in the loss of mangrove and

seagrass habitat.

The indirect impacts of the climate-induced changes to essential

habitats (including the open ocean) on the fish and shellfish

resources have not been widely monitored or reported, and are

indeed difficult to separate from the whole level of changes

occurring within these habitats that have been largely caused by

other anthropogenic stressors. However, there are several

studies providing evidence on the decline in live coral cover,

caused largely by temperature-induced mass coral bleaching, as

well as decline in herbivorous reef fish biomass across the

Caribbean.

Climate change impacts on commercially important fish and

shellfish will have a wide array of social and economic

implications in Caribbean SIDS including impacts on: (1)

consumers and value of the food as a resource with potential

repercussions for food and job security for the fisheries; (2)

recreational diving (e.g. SCUBA and snorkelling) in these areas

with potential reduction in revenue; and 3) the ecological

functions provided by fish and shellfish, mainly on the regulation

of ecosystem services (more details are provided in Oxenford

and Monnereau, 2017).

Furthermore, studies to date have not shown direct evidence of

reduced calcification by Caribbean fish or shellfish, although

there is worldwide evidence of potential observed effects on

some of these species elsewhere from laboratory and field

studies that may help to inform these stocks.

Seagrasses

Seagrasses are considered to be ecologically important

environments as they host and provide a range of ecosystem

goods and services (Guannel et al., 2016; Waite et al., 2014; de

Goot et al., 2012; Polidoro et al., 2010; Waycott et al., 2009;

Cooper et al., 2009; Constanza et al., 2008). These habitats

contribute significantly to the well-being of small island

communities. These ecosystems are generally distributed along

the coast in shallow water where sunlight penetration is

adequate to allow photosynthesis. Their location leaves them

highly susceptible to run-off from land-based activities and to

stressors arising from water sports. Seagrasses play a

significant role in stabilising the seabed and for providing habitat

to juvenile fishes and importantly commercial species (e.g.

conch and lobster) which are consider to be ecosystem

components. Their contribution is mainly as primary producers

in the food chain of the reef community, with their production of

4000 g C/m2/yr. Seagrasses also actively contribute to: i)

nitrogen fixation; ii) habitat provision (mainly for feeding,

breeding and recruitment for juveniles and adults) of reef

organisms (e.g. commercial species and the culturally important

sea egg urchin (Tripneustes ventricosus)); iii) reduction in

sediment movement in nearshore waters and removing

sediments from the water column; iv) decreasing turbidity of the

water; and vi) stabilizing and protecting the coastline during

storms (Guannel et al., 2016;).

These habitats help to maintain ocean clarity, helping to support

tourism and recreation (e.g. snorkelling). Some of the non-

climate change effects on these habitats can be expected from

siltation (arising from shore construction) as well as pollution

sources, smothering and damaging the blades of the

seagrasses. Some of the general evidence presented in the

Caribbean area states that potential expected effects of climate

change can result from sea level rise, ocean acidification,

intensified storms and increased sea surface temperature. Some

specific information is described below for individual SIDs.

In Anguilla, there is limited evidence on the effects of climate

change on seagrasses. However, climate change remains to be

a relatively new threat to these ecosystems. Therefore, there

have been limited studies on distinct climate change impacts on

seagrasses. Nevertheless, some of the potential threats

identified may arise from SLR, changes in localised salinity,

increased SST and effects from extreme weather events.

Generally, as it is expected for coral reefs, similar effects may

arise from SLR, which will reduce the sunlight and could also

have repercussions for the integrity of seagrass beds. In Antigua

& Barbuda and Saint Lucia the main identified potential impacts,

are associated with an increased SST and could affect seagrass

beds in this area. However, there is a limited understanding on

what could be the magnitude of these effects on these habitats.

Some available evidence has suggested that the photosynthetic

mechanism of tropical seagrasses could become damaged at

very increased temperatures (see Campbell et al., 2006).

In the Bahamas, seagrass beds are well-known for their

significant role as seabed stabilizers and in habitat provision to

juvenile fishes and commercial species (mainly conch and

lobster) (Caribsave report-The Bahamas, 2011). The Bahamas

has recognised the importance of these habitats and adopted

strict control and regulation on Environmental Impact

Assessments. These considerations are applicable with regards

to several tourism expansions and take account how these

developments will be likely to affect several habitats (including

mangroves, seagrass beds and coral reefs). In Barbados and the

Dominican Republic, four species of seagrasses have been

identified, these are: Thalassia testudinum (turtle grass),

Syringodium filiforme (manatee grass), Halodule wrightii (shoal

grass) and Halophila spp. (Caribsave report- Barbados, 2011;

Caribsave report- The Dominican Republic, 2011). The majority

of the seagrass beds in the Dominican Republic lie within

protected areas, although some of these coastal ecosystems are

still subjected several threats. These are mainly sedimentation

from river outflows, agro-chemical pollution, and pressures from

coastal developments. Furthermore, the effects resulting from

overfishing and destructive fishing practices are also damaging

these seagrass habitats. Seagrasses are very sensitive to

changes in the surrounding water so they are considered to be

important “indicator species” of the general health of coastal

ecosystems. In Belize, seagrass beds (such as T. testudinum

and S. filiforme) are distributed throughout the entire length of

Belize (Caribsave- Belize, 2011). These beds support large

populations of manatees, which are an important eco-tourism

attraction in the tourism centres of San Pedro, Caye Caulker and

Placencia.

In Grenada seagrass beds are found along the east central and

southern coasts in the Telescope area and within the barrier type

reef extending from Grenville Bay to Prickly Bay in the south.

Most of the reefs and seagrasses continue to be negatively

impacted by tourism activities and over-fishing. In Jamaica, there

is limited evidence on climate change impacts on seagrass beds,

although recent evidence suggests that the proximity of

seagrass beds to coral reefs exposes them to similar climatic

change impacts. As with corals, SLR may reduce the available

sunlight to seagrass beds and hence reduce their productivity.

While there is no consensus amongst the models as to whether

the frequencies and intensities of rainfall on the heaviest rainfall

days will increase or decrease in the region (Simpson, et al.,

2010), increased rainfall could mean localised decreased salinity

and thus decreased productivity of seagrass habitats. At Nevis,

some effects on seagrasses were observed in the 1990s. It is

generally conceded that seagrasses around Nevis, especially

around Charlestown, were "slowly disappearing" (Robinson,

1991). There is clear evidence that some factors have

contributed to the degradation of coral reefs and seagrasses; a

result of anchor damage and sedimentation, shipping-related

pollution and land-based run-off. These effects have caused

physical damage to seagrasses and reduced the quality of

coastal water (Eckert & Honebrink, 1992). Saint Vincent and the

Grenadines (SVG) possess a wide range of seagrasses beds,

these are found along the shoreline in shallow water where

sunlight penetration is adequate to allow photosynthesis. There

has been very little mapping and monitoring of these ecosystems

on the main island of St Vincent. Some maps are available on

the Marsis website (see

http://www.grenadinesmarsis.com/Files_and_Maps.html) for the

Grenadines and these seagrass beds tend to be relatively small

and isolated. Overall, most of the information available has

helped to document seagrass distribution and effects from a

wide range of human activities. However, the current knowledge

on climate change effects on these habitats is limited and mostly

speculative from other habitats (e.g. corals and mangroves).

Overall, the effects of climate change on seagrasses remain

largely uncertain. Potential threats may arise from SLR, changes

in localised salinity, increased SST and intensity of extreme

weather events. As with corals, SLR may reduce the sunlight

available to seagrass beds and hence reduce their productivity

(Nurse et al., 2014). While there is no consensus amongst the

models as to whether the frequencies and intensities of rainfall

on the heaviest rainfall days will increase or decrease in the

region, increased rainfall could mean a localised decrease in

salinity and resulting decrease in productivity of seagrass

habitats. On the other hand, CO2 enrichment of the ocean may

have a positive effect on photosynthesis and growth. The

photosynthetic activity of dense seagrass stands have been

shown to increase local pH potentially balancing a decreased pH

from projected ocean acidification (Bjork & Beer, 2009). An

increase of CO2 levels may also increase the production and

biomass of epiphytic algae on seagrass leaves, which may

adversely impact seagrasses by causing shading; thus changes

may occur in the competition between seagrass species and

between seagrasses and algae (Beer and Koch 1996).

Seagrasses are sensitive to thermal discharges and can only

accept temperatures up to 2-3°C above summer temperatures

(Anderson, 2000). However, the impact of increased SST on

seagrass beds in the Caribbean is uncertain, since studies have

suggested that the photosynthetic mechanism of tropical

seagrasses becomes damaged at temperatures as high as 40-

45°C indicating that they may be able to tolerate temperature

increases above some climate change model projections

(Campbell, et al. 2006).

Turtles-nesting beaches

A vulnerability analysis of CARICOM nations to SLR and

associated storm surge indicated that large areas of the

coastlines in the Caribbean are highly susceptible to erosion.

The beaches have clearly experienced accelerated erosion in

recent decades. Some specific calculations tend to suggest that

beach nesting sites for sea turtles are at significant risk to beach

erosion (Simpson, et al., 2010). Overall, the expected effects of

climate change on nesting sea turtles tend to indicate that there

are potential expected effects on these habitats. Building,

coastal infrastructure and the removal of vegetation from

beaches is leading to erosion of sand and loss of nesting sites.

Beach erosion in several countries, including Tobago, St Lucia,

Grenada, Jamaica and others, is being exacerbated by illegal or

unregulated sand mining. These activities further undermine the

quality and quantity of turtle nesting sites.

Climate change impacts on the biodiversity of beaches may also

be seen as warmer average daily temperatures affect marine

turtles. Incubation temperature influences the sex of baby turtles.

Therefore, it is expected that warmer temperatures may skew

sex ratios in developing eggs and thereby reduce the

reproductive capacity of sea turtles. Such impacts will mean a

further threat to species that are already critically endangered

and a loss of potential revenue for the country’s expanding

tourism industry with an overall disruption of the marine

ecosystem balance.

The following section highlights impacts of climate change on

turtle nesting sites, as well as measures to reduce impacts at a

SIDs level.

A dedicated vulnerability assessment conducted in St Lucia

with regards to SLR, have demonstrated that that newly

adopted measures to minimise SLR effects will have direct

effects on turtle nesting beaches (Murray and Tulsie, 2011).

Some of these species will be also at significant risk to beach

erosion associated with SLR, with 51% significantly affected by

erosion from 1 m SLR and 62% by erosion associated with 2 m

SLR (Simpson et al., 2010).

In Dominica, St. Lucia and Grenada there are documented

impacts of tropical cyclones between 1979 and 1995 which show

the severe erosion that these weather systems have caused to

beaches. In Dominica, in most instances large amounts of sand

were removed and in the cases of Scott’s Head Beach, Rock-a

way Beach and Toucarie Beach, have been replaced with

boulders. Beach profile monitoring has revealed that although

beaches in Dominica have shown signs of recovery after

extreme weather events, they had not yet returned to pre-

hurricane conditions by the time of reporting in 2011 (Caribsave

Report-Dominica, 2011.). An example of an extreme event was

during the struck of Hurricane Lenny struck Grenada in 1999

severely eroding the Grand Anse beach so that the shoreline

retreated inwards by 6 m (Caribsave Report-Grenada, 2011).

Subsequently, Hurricane Ivan in 2005 also reported major

damage to beaches. The following year Hurricane Emily struck

the island and although the damage was less severe than that

experienced by Ivan, the overall impacts reversed any progress

that had been initially made.

In Belize, the Belize Turtle Watch Program was launched in

March 2011 by ECOMAR, in partnership with the Belize

Fisheries Department, with support from World Wide Fund

(WWF) and Protected Areas Conservation Trust (PACT). The

aim is to increase the level of knowledge on sea turtles in

Belize and to establish a baseline data set on abundance and

nesting beach activity so that changes over time, specifically

those caused by climate change, can be measured.

Non-native or Invasive Alien Species

There is limited information for some of the SIDS regarding the

threat of Invasive Alien Species (IAS) and the risks that these

species will pose to the native biodiversity. Invasive species can

out-compete native species for food and space and may even

prey on native species, thus disrupting ecosystems, particularly

those that have already been disturbed and affected as a

consequence of human activities.

Since 2011, during July and August some of the islands (e.g.

Anguilla, Saint Vincent and the Grenadines, Barbados, St

Lucia, Antigua) have experienced exceptionally large

accumulations of Sargassum seaweed Sargassum fluitans

(Figure 2). Since this seaweed has been washed ashore and it

is not originally form these Islands, it is considered to be an

introduced species. These large quantities of the seaweed are

causing concerns among visitors and residents. Although these

events are not confirmed as climate change related effects, the

phenomenon is thought to be as a direct result of the gyre in

the Atlantic off Brazil (see Sargasso sea (Doyle and Franks,

2015). These floating mats of vegetation arrive in the

Caribbean region annually, but over recent years they appear

to be doing so in unusually large quantities. Fishers have

complained that their nets and lines become entangled in the

Sargassum and this has almost shut down the entire fishing

sector. There is also concern over the risk of disease and

invasive species that may accompany the seaweed. The large

volume and weight of seaweed washed up on some beaches is

unsightly and poses a problem for the tourism industry as well

as a major expense and logistical challenge for governments

who opt to collect and dispose of the Sargassum. If this event is

indeed related to cyclonic storms that have formed in the

Atlantic since the 2011 hurricane season, then coastal and

marine environmental managers should prepare for the

likelihood of these events occurring with increased frequency in

the near future.

In Saint Lucia and Nevis the invasive Indo‐Pacific lionfish

(Pterois volitans), has been sighted (recorded since November

2010) in neighbouring territories as close as Guadeloupe and

Venezuela (Figure 3). The lionfish has been observed in the

Western Atlantic, Caribbean and in the Gulf of Mexico (Atkins et

al., 2012; Green et al., 2012; Atkins et al., 2012). The lionfish

have no apparent natural predators in the Caribbean and this

has allowed the species to spread very rapidly throughout the

region from both northern and southern ends of the Caribbean

Basin. The fish feeds not only on reef fish such as parrotfish,

which are important to maintaining reef health, but also on the

juveniles of commercially important species. The St Lucia’s

Fisheries Division and Coastal Zone Management Unit are

greatly concerned about the threat this could pose for the

country’s fishing industry. Some regional research on lionfish is

increasing and should be monitored closely for management

recommendations. (see

http://www.gcfi.org/Lionfish/Lionfish.html for further additional

information). Although there is no evidence that the lionfish

invasion is climate-related, the concern is that when combined

with pre-existing stress factors the natural resilience of

Caribbean reef communities will decrease (Green et al., 2012;

Albins and Hixon, 2013), making them more susceptible to

climate change.

An overall threat to Jamaica’s reefs and fisheries is the voracious

predator lionfish. As of 2010 almost every reef of Jamaica has

uncounted numbers of this invasive species which could wipe

out the already depleted fishing industry (Neufville, 2010).

Overall, there is limited information on invasive species in some

of the islands and the information available is still in its infancy.

There is a need to document sightings and distribution of these

species. Furthermore, it is also important to assess the

ecological trade-off that the invasive species will have over the

native fauna to gain an understanding on the overall

repercussions for biodiversity effects in these areas.

Image 2. Large accumulations of Sargassum fluitans, known as

'the sargassum seaweed' in the Caribbean. (image

©H.Oxenford extracted from Doyle and Franks, 2015).

Image 3. The invasive Indo-Pacific lionfish Pterois volitans.

(©Peter Randall, Cefas)

There is clear concern on the risks to small islands from climate

change effects, which could be originating well beyond the

borders of specific countries and/or islands. These

transboundary processes could have a negative impact on small

islands with strong evidence that this may be the case. For island

communities, the risks associated with existing and future

invasive species and human health challenges are projected to

grow under climate change effects (Nurse et al., 2014). The

effects of climate change may act as a multiplier of existing

health conditions. Other broader effects may affect the health of

the country's fisheries, tourism sector, as these activities are

directly interlinked with the overall health of its marine

environment, whose vulnerability is likely to be exacerbated by

the anticipated effects of climate change” (see more details on a

vulnerability report by Murray and Tulsie, 2011).

Marine mammals

Marine mammals are spotted in most of the islands (e.g. The

Bahamas, Saint Lucia, Belize, Dominica, Granada, Jamaica and

Saint Vincent and the Grenadines). The majority of species are

dolphins (e.g. the common bottlenose, Atlantic spotted and the

spinner). There are also 4 species of migratory whales: minke,

sperm, beaked shortfin and humpback, which are often sighted.

Sperm whales appear to be sighted in greater numbers from the

months of October to January and humpback whales are seen

migrating only between January and April. Dolphins and whales

contribute to recreational tourism in the area, bringing a number

of tourists over the years and creating jobs and business

opportunities in the area. For example, the whale watching

industry in Saint Lucia grew rapidly over a 10-year period from

65 whale watchers in 1998 to over 16,600 in 2008. Whale

watching tours are now offered by different operators on the

islands with a total of US $1,577,010 in direct and indirect

expenditure in 2008 (O’Connor et al., 2009). The number of stay

over, as well as cruise ship tourists to the region continues to

increase annually, offering a good prospect for expansion of the

market for these tours.

Climate change impacts on the chemical and physical

characteristics of marine waters will have negative

consequences for prey items. Therefore, whale feeding patterns

and distribution may be altered. The whale distribution changes

(e.g. following food over different areas) may have repercussion

for watch tour operators. Information on the biology of many

cetaceans is limited and this makes it difficult to predict the

consequences that climate change may have on them.

Nevertheless, it is likely that changes in global temperature, sea

levels, sea‐ice extent, ocean acidification and salinity, rainfall

patterns and extreme weather events will decrease the range of

many marine mammals (Elliot and Simmonds, 2007). Current

evidence suggests that the migration patterns, distribution and/or

abundance of cetaceans are likely to alter in response to

continued changes in sea surface temperature with global

climate change (Lambert et al., 2010).

In SVG there are twelve species of cetaceans which include

humpback whales, sperm whales, pilot whales, bottlenose

dolphins and spinner dolphins. Bequia is the second largest

island in the Grenadines and is one of the few locations where

whale hunting is still permitted by the International Whaling

Commission due to aboriginal subsistence hunting (Mills, 2001).

In Saint Lucia, the short-finned pilot whale is also distributed and

harvested (Murray pers.comm.).

The decrease in the population of sperm whales documented by

Gero and Whithead (2016) in the Eastern Caribbean of -4.5%

per year in unit size started in about 2010, with numbers being

fairly stable until then. There are several natural and

anthropogenic threats, but no well-substantiated cause for the

decline. It is possible that changes in ocean curents and

temperatures associated with climate change may have been

associated with this decline. The available migratory evidence

suggests that marine mammals will be likely affected by climate

change during some stage in their life-cycles. However, there is

not distinct evidence that will imply at what specific stage or how

these effects may be further influenced by other environmental

stressors. There is a clear expectation that climate change

effects may increase abundance or distribution range.

Additionally, climate change could also contribute to higher risks

of extinction for some of the most vulnerable species. One of the

most critical effects resulting from climate change have been

associated with oceanographic changes, which could have

severe repercussions for food availability (mainly fish and

plankton) for marine mammals.

Plankton

The available evidence for most of the islands (e.g. Anguilla

Belize, Grenada, Dominica, Saint Lucia, The Dominican

Republic, Nevis and SVG), and the overall Caribbean area, is

based on the available evidence via the Intergovernmental Panel

on Climate Change- IPCC (A4 and A5 assessments- Nurse et

al., 2014 and IPCC, 2007). Overall, there is an indication that

shifts in plankton abundance will be likely to be affected by rising

water temperatures, changes in ice cover, salinity, acidification,

oxygen levels and circulation, as well as other species (e.g.

algae and fish abundance). Recent studies conducted in the

southern Caribbean areas, showed decreasing levels of

plankton production, from the result of a reduction in ocean

upwelling, whereby nutrients crucial for plankton production are

brought from the sea floor to the surface. The decrease in

upwelling has, in turn, been driven by changes in wind patterns

and wind strength, themselves driven by global climate change,

which may have repercussions for the sardine fisheries. Most of

the available information on plankton and the likely

consequences resulting from climate change effects are based

on wider information from regional assessments (Nurse et al.,

2014). Whilst, this information is accurate, there are no clear

future plankton predictions or expected effects observed in

Caribbean islands. However, the perception is that climate

change will modify oceanographic conditions and therefore

plankton distribution may be affected in the future, with potential

repercussions for higher trophic levels.

Responding to impacts – what is

already happening?

Most Caribbean islands have a great economic dependence on

tourism. Coastal resources including beaches, coral reefs,

seagrass beds, and mangroves offer important protection to

tourism infrastructure as well having aesthetic value, visited

every year by many tourists. Some of the areas have

experienced severe tropical storms, hurricanes and storm surge

damage to these natural resources in the past. There are some

efforts to adopt structural protection (e.g. defences and seawalls)

in some of the areas, but these developments have sometimes

been to the expense of further degradation of many valuable

natural areas. Caribbean societies and economies, the

comprehensive integration of poverty, gender and livelihood

issues into climate change impact and vulnerability assessment

and planning processes is much needed to support the

development of community-specific adaptation strategies. These

activities could help to achieve the sustainable and effective

responses to climate change required from wider Caribbean

societies.

Local knowledge is key to identify where the main resources are

distributed in the area. Furthermore, the current lack of

awareness of where further changes will be expected in the

Caribbean region are of concern. Particularly when there are

clear gaps in the seasonal variability and specific areas where

these species may be distributed and are likely to move (e.g.

depending on their maximum range) as the effects of climate

change may start to become more pronounced. It is necessary

that management, protection and awareness measures are

clearly implemented to safeguard the biodiversity of these areas.

Clearly, there is already ongoing local actions taking place, with

some countries having collectively (e.g. OECS Member States)

developed draft (model and harmonised scenarios) laws since

2006 to manage and safeguard these resources. Some further

support from the local authorities, ensuring that the promulgation

of these local laws can be actively enforced will be

advantageous. There are already some initiatives in place with

regards to Climate Change Adaptation and Disaster Risk

Management in Fisheries and Aquaculture in the CARICOM

Region under the Strategy and Action Plan”. This strategy and

action plan integrates important policy documents. The regional

policy context is primarily based on the ‘Regional Framework for

Achieving Development Resilient to Climate Change’

(considering a Regional Framework), including CARICOM’s

strategy on climate change. The CARICOM Heads of

Government endorsed the Regional Framework at their July

2009 meeting in Guyana and issued the Liliendaal Declaration,

outlining the key climate change aims and interests of CARICOM

Member States. The Liliendaal Declaration is the Implementation

Plan (IP) for the Regional Framework. The CCCCC Regional

Framework is based on five strategy elements and twenty goals.

Overall, these goals do cover aspects of fisheries and

aquaculture under an ecosystem approach. The IP is developed

under the heading of coastal and marine issues. Further

initiatives are looking at improving the outlook for Caribbean

Coral Reefs: A Regional Plan of Action 2013-2018 (e.g. "Coral

reef action plan"). The plan covers components of Strategic

Elements 1: Mainstream CC Adaptation Strategies to

sustainable Development / Agendas of CARICOM Member

States and Strategic Elements 2: Promote the Implementation of

Specific Adaptation Measures to Address Key Vulnerabilities in

the Region of the Regional Framework’s Implementation Plan as

well as other on-going coral reef related initiatives within the

Caribbean region. The key actions can assist coral reef

managers, activities in the coastal zone area, and fisheries

managers and local communities to improve the resilience of

coral reef ecosystems.

Further ongoing work to understand the impacts of climate

change across sectors is the CARIBSAVE Climate Change Risk

Atlas (CCRA) project (several references where used in this

review). The CCRA project synthesise the current evidence-

based, cover several habitats, species and a series of sectors,

which are under threat or may be vulnerable. The report also

included a section on how these different sectors could adjust

their practices and adapt to climate change to enable the

sustainable development of these areas whilst still protecting the

overall biodiversity and equally supporting the economic

development of the Caribbean SIDS. Dedicated effort to

document and illustrate the challenges associated with climate

change on species and habitats, with likely consequences for

biodiversity has been also addressed by governments of Antigua

and Barbuda (CARIBSAVE, 2011a). Grenada is also actively

committed to adapting to climate change, they have also

produced the Strategic Program for Climate Resilience which

includes practices and actions for adaptation and mitigation of

climate change impacts to this island (CARIBSAVE, 2011d). The

Belize Climate Change Adaptation Policy aims to encourage all

government agencies to incorporate climate change aspects in

their activities and overall policies. One of the most important

aspects is to create public awareness and education to support

biodiversity conservation (CARIBSAVE, 2011b).

An example of a climate change initiative in Saint Lucia is the

Pilot Project on “Climate Resilience”. In the health sector, there

are a number of ongoing climate related initiatives. One example

is the need to “Facilitate the design and/or upgrading and

implementation of national programmes for pest and disease

control”, which deals with the areas of vector and water borne

disease monitoring as well as pest and disease monitoring

including invasive species. Another specific project has been

designed to address issues relating to water quality through the

project entitled “Enhancing the Water Quality Surveillance

Programme of the Department of Environmental Health”. This

will be affected through training, as well as the procurement of

equipment for water testing. One final multifaceted project

entitled “Mitigating the Mental Health Impacts of Climate Change

and Climate Variability in Saint Lucia” aims to identify the key

mental health impacts related to climate change events on the

island and assess their implications, as well as to identify ways

to help individuals and communities mitigate and adapt to this

social problem (MFEAND, 2011).

Further development of

understanding to support

adaptation

This review has demonstrated that the majority of the current and

future expects climate change effects are based on broad

information available in the Caribbean Region. However, for

some species and habitats covered in this review there is already

some available evidence, but this is still limited. It is important to

highlight that climate change effects are still perceived as a new

emerging threat in some of these areas. One of the clear

challenges is to disentangle the direct effects resulting from

climate change with other human pressures (e.g. overfishing,

waste treatment, habitat degradations, pH changes, etc.). Some

of the SIDS have made a start and attempted to develop effective

management practices, to protect these valuable species and

ecosystems. Some tangible actions are needed to document

how the extent and distribution of biodiversity is being explored

or developed in these areas. In the sections below, there are

some recommendations that may be useful to set as priorities to

ensure the biodiversity of these islands is preserved and where

necessary restored:

• Adoption of mapping strategies to ensure there is a

baseline of the distribution and extent of these

resources (e.g. seagrasses, sea mammals, invasive

species). This type of information can help to develop a

robust management strategy to protect and monitor

climate change effects.

• Development of an annual monitoring plan

(including water quality, sedimentation rates, fauna,

setting etc.) can help to undertake consistent

assessments to identify cause-effect disturbances

associated with climate change on these habitats and

species. For example, in some areas of the Caribbean

there is The Coral Reef Early Warning Systems

Network (CREWS), with a suite of meteorological and

air-based sensors including air temperature, wind

speed and direction, barometric pressure,

photosynthetically available radiation (PAR) and

ultraviolet radiation (UVR). The basic suite of

oceanographic sensors measure salinity, sea

temperature, PAR (at 1m nominal) and UVR (at 1m

nominal) (for more information visit:

http://www.caribbeanclimate.bz/general/coral-reef-

early-warning-system-crews.html)

• Protection and adoption of ‘No take zones’ as

Marine Protected Areas, helping to provide protection

and refugia for species that may be under threat and to

preserve native socks, and where applicable to enable

recovery of dedicated areas.

• Caribbean Challenge Initiative, some islands have

actively engaged in this ongoing initiative, where there

are dedicated actions to protect 20% of the Caribbean

marine and coastal ecosystems by 2020

(http://caribbeanchallengeinitiative.org/).

• Multidisciplinary research is clearly needed for the

development of more effective conservation strategies.

Networks of Protected Areas (NPAs) are seen as

critically important to the conservation of biodiversity,

but their management is often inadequate or non-

existent. Creating successful NPAs will require the

input of ecologists, social scientists, and economists in

order to develop effective management regimes and

secure the input and support of local communities.

• Consideration of restoration strategies are a type of

approach which could help to enhance areas where

there has been a disturbance or decline of a particular

habitat type. Adequate planning to support

translocation trials could help to repopulate the

damaged habitats (e.g. seagrasses or corals).

• Promotion of knowledge transfer and awareness:

organise dissemination workshops to cascade the

current understanding of climate change effects, and

the importance of preserving habitats and species,

targeted at the general public, conservation end-users,

and policy makers.

• Creating awareness and investment over targeted

projects to understand and disentangle climate and

environmental effects (via monitoring work) in small

islands. There is a clear gap in the lack of empirical data

sets available to understand the present and future

climate change impacts. Climate and environmental

monitoring data is needed to design and implement

management practices to safeguard these areas

(Nurse et al.,2014).

• Investment and development of ‘fit for purpose’

climate change-related projections, which build on

the current work conducted on temperature and sea

level. The available climate-model projections of

temperature and sea level have been useful, but there

is clearly a need to develop projections for other

variables (pH changes, wind direction, tropical storms,

etc.), which are important to small islands.

Citation

Please cite this document as:

Birchenough, S.N.R. (2017) Impacts of Climate Change on

Biodiversity in the Coastal and Marine Environments of

Caribbean Small Island Developing States (SIDS), Caribbean

Marine Climate Change Report Card: Science Review 2017, pp

40-51.

The views expressed in this review paper do not represent the

Commonwealth Marine Economies Programme, individual

partner organisations or the Foreign and Commonwealth Office.

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