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Complex marine food web of linkages between pelagic and benthic communities. Gray lines indicate linkages from benthic communities up the food web, and black lines indicate linkages from pelagic communities down the food web. In marine systems, the primary trophic levels can be categorized into groups including top large carnivores (e.g., sharks, marlin), smaller carnivores (e.g., tunas, salmon), planktivores (e.g., baitfishes, herring), herbivores (e.g., parrotfishes), and detritivores (e.g., benthic invertebrates).
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Marine protected areas (MPAs), ideally, manage human uses that threaten ecosystems, or components of ecosystems. During several recent MPA designation processes, concerns have arisen over the scientific justification for no-take MPAs, particularly those that restrict recreational fishing for pelagic species. An important question is: under what con...
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... food webs can be highly complex, with an extraordinary number of interactions among a large diversity of species, with energy-often in the form of preymoving across many gradients ( Cohen et al. 2003). Figure 1 illustrates this complexity for the Northern California Current shelf ecosystem, highlighting the importance of understanding the nature, direction, and strength of interactions among different trophic levels (adapted from Field et al. 2006). The colors represent alternative energy pathways. ...
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... The proposition of stratifying conservation effort by depth 11,74 has gained momentum with the increasing recognition of area-based fisheries management as OECMs, which commonly only confer protection to the benthos 2 . This assumes that human impacts remain compartmentalized to the depths where human uses occur, which overlooks numerous connectivity processes across depths. ...
The wave of new global conservation targets, the conclusion of the High Seas Treaty negotiations, and the expansion of extractive use into the deep sea call for a paradigm shift in ocean conservation. The current reductionist 2D representation of the ocean to set targets and measure impacts will fail at achieving effective biodiversity conservation. Here, we develop a framework that overlays depth realms onto marine ecoregions to conduct the first three-dimensional spatial analysis of global marine conservation achievements and fisheries footprint. Our novel approach reveals conservation gaps of mesophotic, rariphotic, and abyssal depths and an underrepresentation of high protection levels across all depths. In contrast, the 3D footprint of fisheries covers all depths, with benthic fishing occurring down to the lower bathyal and mesopelagic fishing peaking in areas overlying abyssal depths. Additionally, conservation efforts are biased towards areas where the lowest fishing pressures occur, compromising the effectiveness of the marine conservation network. These spatial mismatches emphasize the need to shift towards 3D thinking to achieve ocean sustainability.
... Moreover, marine habitats distributed along the vertical gradient are physically and biologically closely linked within the benthonic-pelagic coupling (Griffiths et al., 2017). A constant flux of energy, nutrients, and gases moves from the seafloor toward the sea surface throughout the water column and vice versa (Danovaro et al., 1999), as well as marine species, move from one layer to another, structuring interconnected food webs (Grober-Dunsmore et al., 2008). Hyperbenthic environment hosts high biodiversity of marine organisms with strong trophic links, with species inhabiting the upper and lower layers (Koulouri et al., 2013). ...
This study investigates the abundances and composition of microplastics (MP) among the shallow layers of a coastal Mediterranean Marine Protected Area (Cabrera MPA), seafloor sediments, hyperbenthic environment, and the water column. The mid waters samples were collected mid-way between the sea surface and the seafloor and hyperbenthic samples at the water layer adjacent to the seafloor. Sampling was carried out on patchiness seafloor of Posidonia oceanica meadows. The seafloor sediments showed a mean abundance of 378,769.20 ± 508,109.11 MPs/m3, three orders of magnitude higher than the hyperbenthic (209.17 ± 117.07 MPs/m3), and the mid waters layer (106.48 ± 107.17 MPs/m3). An increasing vertical gradient in MP abundances, mainly composed of fibers was observed. Fibers were made-up mainly of polystyrene (PS, 25 %), expanded polystyrene (EPS, 18 %) and cellulose acetate (CA, 16 %). The results stress the need to increase efforts to find solutions to mitigate fiber pollution in the marine environment.
... The relatively low productivity, weaker governance, and data deficiency of the open ocean make it difficult to determine what level of fishing activity targeting pelagic and deep-sea species is sustainable (Collette et al., 2011;Norse et al., 2012;Ortuño Crespo and Dunn, 2017;Palomares et al., 2020;Pauly et al., 2020). Furthermore, the two-way coupling between offshore benthic and pelagic systems means that impacts in the upper parts of the open ocean, which are more commonly fished, cascade through the entire vertical span of offshore assemblages (Grober-Dunsmore et al., 2008). ...
... Mapped features of the open ocean are often areas of high productivity, diversity or significant ecological processes, and need to be protected in their entirety to allow for the full range of ecological processes to take place. Hyrenbach et al., 2000;Sibert et al., 2000;Sibert and Hampton, 2002;Alpine and Hobday, 2007;Grober-Dunsmore et al., 2008;Sutton et al., 2008;Long et al., 2013;Garrigue et al., 2015;Rigby et al., 2019;Lecours et al., 2020 7a. Have at least three replicate no-take MPAs: within bioregions; of very large features (e.g., topographic or hydrodynamic features); and of known habitats and ecological processes. ...
... Vertical zoning (applying different management rules to benthic and pelagic habitats of the same area) is also not recommended (Grober-Dunsmore et al., 2008;Lausche, 2011). ...
Networks of no-take marine protected areas (MPAs), where all extractive activities are prohibited, are the most effective tool to directly protect marine ecosystems from destructive and unsustainable human activities. No-take MPAs and MPA networks have been globally implemented in coastal seas, and their success has been significantly enhanced where science-based biophysical guidelines have informed their design. Increasingly, as human pressure on marine ecosystems is expanding further offshore, governments are establishing offshore MPAs—some very large—or MPA networks. Globally, there are growing calls from scientists, non-government organisations, and national governments to set global conservation targets upwards of 30%. Given that most of the ocean is found either in the high seas or offshore within national Exclusive Economic Zones, large offshore MPAs or networks of MPAs must be a major component of these global targets for ocean protection. However, without adequate design, these offshore MPAs risk being placed to minimise conflict with economic interests, rather than to maximise biodiversity protection. This paper describes detailed biophysical guidelines that managers can use to design effective networks of no-take MPAs in offshore environments. We conducted a systematic review of existing biophysical design guidelines for networks of MPAs in coastal seas, and found consistent elements relating to size, shape, connectivity, timeframes, and representation of biophysical features. However, few of the guidelines are tailored to offshore environments, and few of the large offshore MPAs currently in place were designed systematically. We discuss how the common inshore design guidelines should be revised to be responsive to the characteristics of offshore ecosystems, including giving consideration of issues of scale, data availability, and uncertainty. We propose 10 biophysical guidelines that can be used to systematically design offshore networks of MPAs which will also contribute to the global goal of at least 30% protection globally. Finally, we offer three priority guidelines that reflect the unique conservation needs of offshore ecosystems: emphasising the need for larger MPAs; maximising the inclusion of special features that are known and mapped; and representing minimum percentages of habitats, or, where mapped, bioregions. Ultimately, MPA guidelines need to be embedded within an adaptive management framework, and have the flexibility to respond to emerging knowledge and new challenges.
... Besides horizontal zoning approaches, there are attempts of vertical zoning by considering benthicpelagic coupling or by protecting seamounts which reach from the seabed through the water column (Fitzsimons and Wescott, 2008;Grober-Dunsmore et al., 2008;OSPAR Commission, 2019b). ...
... In the HD, the pelagos is not yet considered as a habitat(Annex I EU, 1992;Boero et al., 2019), even though it is a key habitat(EASAC, 2016;Boero et al., 2019). Although vertical zoning is being applied in the management of some MPAs(Kelleher and Kenchington, 1992), therewith taking into account the water column(Game et al., 2009), this approach is usually limited to restrict fishery activities(Grober-Dunsmore et al., 2008). Fisheries however is not the only human activity, which adversely impacts the water column. ...
Maritime Spatial Planning (MSP) is an emerging tool for spatially allocating marine uses by applying an ecosystem-based approach to achieve sustainable development. Despite pressing issues like envi- ronmental degradation and approaching deadlines of political agreements, the environmental recog- nition in MSP lags behind the fast progress of economy-driven developments at sea. To achieve ade- quate marine protection, a term specifically used in this Thesis, it is necessary to look at the bigger picture of the seas altogether and make use of MSP differently from how it is currently done. This Thesis aims to identify the shortcomings in MSP from an environmental perspective. In order to ex- amine how well both structural (biodiversity) and functional (ecosystem functioning) components of the marine environment are integrated into the current MSP processes of the European Union, the maritime spatial planning of the German Exclusive Economic Zone (EEZ) is exemplarily investigated by means of a Qualitative Content Analysis. The German MSP documents are scanned for previously developed keywords, which are derived from and connected to the Cells of Ecosystem Functioning (CEF) concept. Spurred by knowledge gaps identified from the analysis, this Thesis formulates rec- ommendations on how MSP can significantly contribute to a healthy, biodiverse and productive ma- rine environment as envisioned by the European Union.
... Assessing MPA effectiveness to mitigate heatwave induced community structure shifts. Just as species with different traits may respond differentially to climate drivers [38][39][40] , they also react uniquely to different conservation measures 3,22,29,[40][41][42] . Using linear mixed models, we found that MPAs did not mitigate the observed community shifts in numerical density resulting from the marine heatwave (Fig. 3). ...
Acute climate events like marine heatwaves have the potential to temporarily or permanently alter community structure with effects on biodiversity and ecosystem services. We aimed to quantify the magnitude and consistency of climate driven community shifts inside and outside Marine Protected Areas before and after a marine heatwave using a kelp forest fish community dataset in southern California, USA. Abundance, biomass, diversity and recruitment of warm-water affinity species during the marine heatwave were significantly greater compared with prior years yet cool-water affinity species did not show commensurate declines. Fish communities inside MPAs were not buffered from these community shifts. This result is likely because the particular species most responsible for the community response to environmental drivers, were not fisheries targets. Resource managers working to preserve biodiversity in a changing climate will need to consider additional management tools and strategies in combination with protected areas to mitigate the effect of warming on marine communities.
... Species of megafauna typically occupy multiple trophic levels throughout their life cycle and many are considered an upper trophic level functional group (Ferretti et al., 2010;Okey et al., 2004). Thus, megafauna reduction can potentially produce ecological cascades, disrupt the flow of energy between benthic and pelagic assemblages and communities (Grober-Dunsmore et al., 2008;Ruiz et al., 2016), and modify marine ecosystems (Okey et al., 2004;Ruppert et al., 2013). In addition to their ecological value, megafauna species are also essential for marine-based tourism in many areas of the world, driving local economies and supporting coastal communities (Farr et al., 2014;Lynham et al., 2015;O'Malley et al., 2013;Vianna et al., 2012). ...
Marine megafauna (elasmobranchs, marine mammals, turtles, and seabirds) are important ecologically and economically because many species often occupy upper trophic levels as adults and are essential for marine-based tourism in many areas of the world. This group of species is also heavily impacted by fishing because most have late sexual maturity, longevity, and low reproductive output, which affects their ability to recover from depletion. In Galapagos, marine megafauna species are protected from fishing throughout the marine reserve and are the main attraction for marine-based tourism, helping generate millions of dollars in revenue annually. Despite their importance in the archipelago, these species are being caught as bycatch in the multiple artisanal longlining projects that have been carried out since the implementation of the reserve in 1998. Longlining was originally proposed as a way of redirecting fishing effort from the severely depleted coastal-demersal species to pelagic fish such as yellowfin tuna and swordfish. Although all these projects have resulted in high bycatch of megafauna, longline fishing projects have continued without independent scientific studies to evaluate their impact, largely due to poor objective definition, data collection, and enforcement. To fill in this knowledge gap, we analyzed data of the fifth experimental longline fishing project undertaken in 2012–2013 to describe the fishery, identify variables affecting the composition and quantity of bycatch, and suggest mitigation strategies. This experimental project had twelve vessels, which deployed 42,007 hooks catching 4893 individuals of 33 species, mostly yellowfin tuna and swordfish. Of those, 16 species were protected megafauna, particularly blacktip sharks (Carcharhinus limbatus) and oceanic manta (Mobula birostris). These species were regularly captured during the two seasons and in the three bioregions that occur in the archipelago, suggesting little potential to mitigate their catch. As an alternative, we identified 14 hotspots where yellowfin tuna and swordfish could be harvested in large numbers sustainably through more selective fishing techniques such as pole fishing, a method that is also more economical for artisanal fishers. In an archipelago where the main economic activity is marine wildlife tourism, the implementation of an extractive and unselective activity such as pelagic longing fishing should be avoided to ensure the sustainability of the Galapagos marine ecosystem and its booming tourism industry.
... In the open ocean, vulnerable habitats in need of protection are disproportionately perceived to be those on the seabed, especially the deep-sea because of the visibility of direct impacts from fishing and awareness of lengthy recovery times (Clark et al., 2016;Jones et al., 2017). The water column is seen to be much less at risk, a judgement based on the absence of fixed habitat structures that fishing gears might damage (Fitzsimons and Wescott, 2008;Grober-Dunsmore et al., 2008). Indeed, arguments are often made that there is little point in water column protection due to the mobility of the organisms that inhabit it (Game et al., 2009). ...
... Shallow-water and topographically complex habitats, and areas characterised by predictable oceanographic conditions such as upwellings, are often considered to have stronger links between the seabed and water column than surface vs. deeper waters (Grober-Dunsmore et al., 2008). However, this perspective is likely to have developed not because of real biological differences in structure and function, but rather due to a variety of other factors. ...
... For pragmatic reasons, decision-makers often prioritise multiple-use areas in MPAs, thereby maximising the volume of ocean that remains open to fishing (Costello and Ballantine, 2015). Many argue that while pelagic fisheries may result in some indirect effects to seabed communities, these are not comparable to impacts from bottom fisheries and therefore demand fewer restrictions (Grober-Dunsmore et al., 2008). While the prevention of physical destruction of seabed habitat should be of high conservation priority given its irreversibility on meaningful timescales (Clark et al., 2016;Jones et al., 2017), so too should be protection of the water column above these habitats to safeguard linkages that are likely to be essential for full seabed functioning. ...
Coastal nations have embarked on a rapid program of marine protected area (MPA) establishment, incentivised by the approaching 2020 deadline of United Nations global marine protection targets. Alongside, efforts are underway to extend protection into areas beyond national jurisdiction through a new international legally binding instrument. These developments are welcome but there are risks that in meeting them, nations will still fail to supply adequate protection to marine life. An increasing number of MPAs protect the seabed while the water column remains open to fishing. This is because vulnerable habitats in need of protection are disproportionately perceived to be those on the seabed, while the water column is viewed as much less at risk. The seabed and water column are, however, inextricably linked. Transitions between human-defined vertical ocean zones are blurred, with animals and oceanographic features moving across depths. Here, we explore a rapidly growing literature on ecological and environmental connections through the water column, and between the water column and the seabed, to consider whether vertically stratified management is justified from an ecological standpoint. We find that emerging research increasingly links upper-ocean communities and processes to seabed ecology and biogeochemistry suggesting that exploitation of the water column is likely to have a significant and widely distributed footprint in the deep-sea. We conclude that there is a strong a priori case for surface to seabed protection within MPAs, and that this should be the default, precautionary approach to safeguard intact ecosystems with as near to natural function as possible.
... Such studies tend to use survey techniques such as trapping, fishing, camera recordings and Underwater Visual Census (UVC). Fish survey methods that provide more detail on the mid-water component within MPAs may also reveal how pelagic species and the benthic-pelagic coupling respond to protection, an area of research that comparatively, is lacking 13,15,16 . In this respect, active hydroacoustics have the advantage that they can sample almost the entire water column 17 , whereas Underwater Visual Census (UVC) is focussed predominantly on demersal species (i.e. from the seabed to a given height above it). ...
Hydroacoustic technologies are widely used in fisheries research but few studies have used them to examine the effects of Marine Protected Areas (MPAs). We evaluate the efficacy of hydroacoustics to examine the effects of closure to fishing and habitat type on fish populations in the Cabo Pulmo National Park (CPNP), Mexico, and compare these methods to Underwater Visual Censuses (UVC). Fish density, biomass and size were all significantly higher inside the CPNP (299%, 144% and 52% respectively) than outside in non-MPA control areas. These values were much higher when only accounting for the reefs within the CPNP (4715%, 6970% and 97% respectively) highlighting the importance of both habitat complexity and protection from fishing for fish populations. Acoustic estimates of fish biomass over reef-specific sites did not differ significantly from those estimated using UVC data, although acoustic densities were less due to higher numbers of small fish recorded by UVC. There is thus considerable merit in nesting UVC surveys, also providing species information, within hydroacoustic surveys. This study is a valuable starting point in demonstrating the utility of hydroacoustics to assess the effects of coastal MPAs on fish populations, something that has been underutilised in MPA design, formation and management.
... Vertical zoning is based on the notion that benthic and pelagic communities are ecologically separate and can be managed separately, but this is compounded by complex interactions and a lack of data to support such approaches in practice. Moreover, from a management standpoint it is very difficult to manage and, if necessary, legally enforce marine activities in such a three-dimensional way, and ensure that the elements of conservation value remain intact (Grober-Dunsmore et al., 2008). IUCN's advice therefore is where vertical zoning does occur the level of protection afforded should be recorded at the lowest level present in the zoning scheme. ...
... Vertical integration in the form of vertical zoning within MPAs has been proposed by Grober-Dunsmore et al. [27], as a means to address benthic-pelagic linkages. Grober-Dunsmore et al. developed a conceptual framework to identify the need for such zonation as part of MPA management planning processes based on the consideration of four elements, namely, water depth, habitat type, predator type, and taxonomic, mobility and life history characteristics of pelagic species. ...
... Grober-Dunsmore et al. developed a conceptual framework to identify the need for such zonation as part of MPA management planning processes based on the consideration of four elements, namely, water depth, habitat type, predator type, and taxonomic, mobility and life history characteristics of pelagic species. With regards to habitat type, for instance, it is known that complex benthic habitats such as reefs and kelp forests have strong linkages with pelagic species, as well as seamounts and canyons [27]. ...
... No globally agreed definition of a VME is available but VMEs constitute areas with characteristics that may be vulnerable to impacts from fishing activities. 27 Specifically this relates to high seas fisheries likely to contact the seabed and the prevention of 'significant adverse impacts' (SAIs). Recommendations and Guidance for the identification of VMEs, based upon potentially vulnerable species groups, communities and habitats (see [66]), were formally negotiated under the auspices of the FAO. ...
This article explores the concept of "other effective area-based conservation measures" (OECMs) in the context of the UN Convention on Biological Diversity (CBD) Aichi Biodiversity Target 11 on marine protected areas and OECMs and its linkages to the Sustainable Development Goals (SDGs). It argues that mainstreaming biodiversity through CBD Aichi Biodiversity Targets' implementation into the SDGs can contribute to a more systemic and comprehensive implementation of SDG 14.5 on conservation of at least 10% of marine and coastal areas. It argues that OECMs can complement MPAs and contribute to ecologically representative and effectively managed marine protected areas systems integrated into broader governance systems such as marine spatial planning. Selected global and local sectoral conservation measures are therefore highlighted in this analysis as potential forms of OECMs. At the local level, a case study of ecologically or biologically significant marine areas managed as locally managed marine areas (LMMAs) in Mozambique is discussed. This case study explores how multiple-use LMMAs, which respond to short-term fisher's needs and targeted biodiversity conservation, could contribute to the achievement of specific SDGs on food security, poverty elimination and resilient ecosystems if properly supported by long-term investments, strong institutions and integrated oceans management.
