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5 The kelp Ecklonia maxima dominates nearshore reefs in the cold waters around southern Africa west of Cape Agulhas. It is a substantial seaweed which can grow to lengths in excess of 15 m (a: Buffels Bay, Cape of Good Hope). Between 2006 and 2008 this species expanded past Cape Agulhas, presumably due to cooling caused by upwelling (b: recently colonized intertidal populations at De Hoop Nature Reserve) (Photos © T. Wernberg)
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The biogeographic boundaries of seaweeds are largely determined by temperature tolerances, physical barriers and limitations to dispersal. Anthropogenic ocean warming and increasing connectivity through human activities are now causing rapid changes in the biogeography of seaweeds. Globally, at least 346 non-native seaweed taxa have been introduced...
Citations
... Speci cally, on Vertebrata lanosa and Ascophyllum nodosum, Garbary (2017) supports that the harvesting of A. nodosum reduces the abundance of V. lanosa. In addition, concerns have been rising globally in regards of the impact of climate change on seaweed abundance, distribution and quality (Straub, Thomsen & Wernberg, 2016), and while some algal groups (e.g. kelps) appear to be more resilient, their biomass availability can vary greatly (Bell et al., 2015;Krumhansl et al., 2016). ...
Vertebrata lanosa is an intertidal red algal species that grows epiphytically on Ascophyllum nodosum, a brown fucoid alga. V. lanosa received culinary interest in the recent years due to its truffle-like taste and it is currently only harvested from natural populations. This study has focused on the growth of the species in lab cultures and investigated the temperature and salinity leading to higher specific growth rate. V. lanosa showed higher growth rate in 10 oC and 30‰. Overall, the study identified optimal temperature and salinity conditions for indoor controlled cultivation of the species and proved that Vertebrata lanosa can be cultivated in absence of its host, A. nodosum. Furthermore, a complete life cycle of V. lanosa has been carried out in culture where all life history phases and stages were observed. Though, to move from experimental culture to a larger scale production, further research is needed both on the cultivation of the species and the biochemical interactions with its host.
Acknowledgements
... The natural distributions of seaweeds are to be largely determined by physiological tolerances, particularly with respect to temperature, physical barriers and limitations to dispersal (Straub et al. 2016). The warming of global oceans is a consequence of anthropogenic activities, and it is now being coupled with accelerated human-mediated movement of species. ...
... climate mediated change). Straub et al. (2016) compared the speed of range-shifts for 40 macroalgal taxa between three drivers: range expansions caused by introductions, and range expansions and contractions attributed to climate change (warming/cooling). They concluded that the range expansions occurred significantly faster than contractions, and climate-driven shifts were significantly slower than introductions. ...
... The development and updating of lists of nonindigenous marine species are important elements in local and global biosecurity and, to be reliable, such inventories require regular updating by local experts (Bailey et al. 2020). Straub et al. (2016) note the need for close monitoring of species range shifts caused by both introductions of nonindigenous species and climate change, and the need for regular surveys building the baseline information (with taxonomically robust identifications) to enable coastal management. As Marchini et al. (2015) note, inventories of alien species have "scientific, political, commercial and social relevance" and thus, the compilation of lists needs to be based on more than just a collation of records from literature, identifying three categories of uncertainty: species' taxonomic identification, species' actual occurrence in an area, and its status as an alien. ...
... Climate change mitigation is an important role of seaweed (Langton et al. 2019). The impact of climate change on seaweed abundance, distribution, and quality is a global concern (Straub et al. 2016). Seaweed has a certain degree of resilience to global climate change (Krumhansl et al. 2016), and its biomass availability can vary on a spatial basis (Bell et al. 2015;Boden et al. 2017). ...
Seaweed production (both culture and natural) has increased compared with in the past. It occupies a strong position in the food supply and meets global food demand. Seaweed emerges as a powerful tool to mitigate and adapt to climate change. It acts as a carbon sink by sequestrating carbon from the atmosphere into the ocean. It can reduce the carbon emission from agricultural fields by improving the soil quality. It also minimizes the emissions of methane gas when mixed in cattle food. Seaweed increases the pH of water thus reducing the ocean acidification phenomena. As a result, aquatic organisms such as finfish, shellfish, corals, and invertebrates find a suitable place to live in. It produces trace gas (e.g., volatile brominated and iodinated halocarbons) that deplete the ozone. Seaweed dampens wave energy during storms and protects the coast as climate change adaptation. Seaweed provides oxygen to the ocean water, which minimizes the issue of de-oxygenation. It offers habitats and food for important components of the marine ecosystem that have a great impact on the climate. Seaweed provides biofuels, fertilizer, medicine, and food for human consumption. In this review, we emphasize the role of seaweed in climate change mitigation and adaptation. Seaweed cultivation can be optimized to get maximum climate benefits and increase the livelihood status of the seaweed farmer.
Link of chapter: https://link.springer.com/chapter/10.1007/978-3-030-71950-0_5
... The natural distributions of seaweeds are to be largely determined by physiological tolerances, particularly with respect to temperature, physical barriers and limitations to dispersal (Straub et al. 2016). The warming of global oceans is a consequence of anthropogenic activities, and it is now being coupled with accelerated human-mediated movement of species. ...
... climate mediated change). Straub et al. (2016) compared the speed of range-shifts for 40 macroalgal taxa between three drivers: range expansions caused by introductions, and range expansions and contractions attributed to climate change (warming/cooling). They concluded that the range expansions occurred significantly faster than contractions, and climate-driven shifts were significantly slower than introductions. ...
... The development and updating of lists of nonindigenous marine species are important elements in local and global biosecurity and, to be reliable, such inventories require regular updating by local experts (Bailey et al. 2020). Straub et al. (2016) note the need for close monitoring of species range shifts caused by both introductions of nonindigenous species and climate change, and the need for regular surveys building the baseline information (with taxonomically robust identifications) to enable coastal management. As Marchini et al. (2015) note, inventories of alien species have "scientific, political, commercial and social relevance" and thus, the compilation of lists needs to be based on more than just a collation of records from literature, identifying three categories of uncertainty: species' taxonomic identification, species' actual occurrence in an area, and its status as an alien. ...
The recognition of non-indigenous marine macroalgae in New Zealand and the potential pathways and vectors contributing to their arrival were discussed by Nancy Adams in 1983 along with a list of 14 species she considered to be “possibly naturalised”. In the following 38 years many more species have been identified as non-indigenous, a few of which have become widespread and invasive around New Zealand. We present an updated list of 61 taxa that we consider to have been introduced to the archipelago, and highlight a range of issues associated with the recognition of non-indigenous species, particularly increased taxonomic knowledge, the impact of an expanded collection baseline, as well as targeted investigations in New Zealand, increasing data availability globally, and the role of molecular tools for confirming species identifications and distinguishing cryptic species.
... High levels of genetic affinity observed between HOK and the south of Korea-Japan indicate the possible occurrence of anthropogenic transportation of genotypes across native ranges. The human-mediated movement of populations from native to introduced regions causes rapid expansion of population distribution and alter natural phylogeographic patterns (Straub et al. 2016). Anthropogenically altered distribution patterns have often been demonstrated in macroalgae with low dispersal capabilities, such as Asparagopsis taxiformis, Symphyocladia dendroidea, and Polysiphonia devoniensis (Andreakis et al. 2016, Díaz-Tapia et al. 2018. ...
... The conspicuous thermally tolerant congeneric kelp (Franco et al., 2017;Hargrave et al., 2017) of Lusitanian origin, L. ochroleuca (Bachelot de la Pylaie), has expanded its range northwards from Morocco and across the English Channel in response to the changing climate over the last century. Today, L. ochroleuca is expanding its leading edge eastwards and northwards at around 5.4 and 2.5 km per year, respectively (Straub et al., 2016). Its range now overlaps substantially with the native assemblage's dominant kelp species, L. hyperborea (Smale et al., 2015;Hargrave et al., 2017) which has undergone a ~250 km range contraction at its warm leading-edge since 1970 (Assis et al., 2016). ...
... The expanding thermal envelope and subsequent spread of L. ochroleuca is modifying both the taxonomic and functional composition of HFS, with resulting effects on detrital composition. The re-arrangement of HFS has been shown to have marked ecological implications; extending to adjacent communities which rely on these subsidies of allochthonous material (Bishop et al., 2010;Straub et al., 2016). ...
Temperate kelp forests contribute significantly to marine primary productivity and fuel many benthic and pelagic food chains. A large proportion of biomass is exported from kelp forests as detritus into recipient marine ecosystems, potentially contributing to Blue Carbon sequestration. The degradation of this organic material is slow and recent research has revealed the preservation of photosynthetic functions over time. However, the physiological correlates of detrital breakdown in Laminaria spp. have not yet been studied. The warming climate threatens to reshuffle the species composition of kelp forests and perturb the dynamics of these highly productive ecosystems. The present study compares the physiological response of degrading detritus from two competing North East Atlantic species; the native Boreal Laminaria hyperborea and the thermally tolerant Boreal-Lusitanian L. ochroleuca. Detrital fragment degradation was measured by a mesocosm experiment across a gradient of spectral attenuation (a proxy for depth) to investigate the changes in physiological performance under different environmental conditions. Degradation of fragments was quantified over 108 days by measuring the biomass, production and respiration (by respirometry) and efficiency of Photosystem II (by PAM fluorometry). Data indicated that whilst degrading, the photosynthetic performance of the species responded differently to simulated depths, but fragments of both species continued to produce oxygen for up to 56 days and sustained positive net primary production. This study reveals the potential for ostensibly detrital kelp to contribute to Blue Carbon fixation through sustained primary production which should be factored into Blue Carbon management. Furthermore, the physiological response of kelp detritus is likely dependent upon the range of habitats to which it is exported. In the context of climate change, shifts in species composition of kelp forests and their detritus are likely to have wide-reaching effects upon the cycling of organic matter in benthic ecosystems.
... The presence of these four taxa may be the result of unnoticed introductions into the region, from ballast water or hull fouling associated with intense shipping by the closeness of the Panama Canal, the latter having been considered one of the most ancient ways for the introduction of alien species in the marine system (Boudouresque and Verlaque 2010). Global ocean warming and increasing connectivity through human activities are currently causing rapid changes in the biogeography of seaweeds (Straub et al. 2016), promoting expansions in the distribution ranges of some species. In that sense, the study area has two possible sources of propagule pressure, the Buenaventura harbor in the south and the Panama Canal in the north, both of them located around 200 km from the sites of collection. ...
We report new records of four macroalgae species in the Eastern Tropical Pacific, specifically from the rocky reefs of northern Chocó, Colombian Pacific. Among them, three species of Rhodophyta are included-Crouania mageshi-mensis Itono, 1977; Monosporus indicus Børgesen, 1931; Jania articulata N'Yeurt & Payri, 2009-and one species of Chlorophyta-Ulothrix subflaccida Wille, 1901. The new records increase the knowledge of tropical marine algae in the Pacific, open the discussion about possible dispersal mechanisms, and recall the importance of conducting molecular studies to define phylogenetic and biogeographic aspects of macroalgae. Citation: Rincón-Díaz N, Gavio B, Sánchez Muñoz JV, Chasqui L (2020) Crouania mageshimensis Itono, 1977 (Ceramiales, Rhodophyta) and new records for three other species of macroalgae from the Eastern Tropical Pacific. Check List 16 (5):
... heatwaves), are having profound impacts on the functional integrity of kelp forests(Connell, 2007; Araújo et al., 2016;Smale et al., 2019). Furthermore, as a consequence of anthropogenic perturbations working in synergy, declining kelp biomass will inevitably impact the supply of kelp detritus into recipient marine communities.The conspicuous thermally tolerant macroalgae(Franco et al., 2017;Hargrave et al., 2017) of Lusitanian origin, Laminaria ochroleuca (Bachelot de la Pylaie), has expanded its range northwards from Morocco and across the English Channel in response to the changing climate.Today, L. ochroleuca is expanding its leading edge eastwards and northwards at 5.4 and 2.5 km per year, respectively(Straub et al., 2016). Its range now overlaps with the native assemblage's dominant kelp species, L. hyperborea(Smale et al., 2015;Hargrave et al., 2017) which has undergone a ~ 250 km range contraction at its warm leading-edge since 1970. ...
... The moving thermal envelope of L. ochroleuca is modifying the functional composition of HFS, with propagating effects on detrital composition. The re-arrangement of HFS has been shown to have marked ecological implications, extending to adjacent communities which rely on these subsidises of allochthonous material(Bishop et al., 2010;Straub et al., 2016). ...
Une large part de la production des forêts de laminaires à Laminaria hyperborea est exportée sous forme de macro-détritus. Ces détritus de laminaires transitent vers les environnements côtiers adjacents et peuvent s’accumuler sur différents systèmes benthiques subtidaux ou intertidaux. L’objectif de ce travail de thèse est de caractériser la dynamique des accumulations et de décrire la cinétique de dégradation ainsi que la communauté de macrofaune associée. Un ensemble de prospections et de suivis, réalisés en plongée, a été mené au niveau du secteur Île de Batz-Baie de Morlaix et montre la présence saisonnière d’importantes accumulations de fragments de laminaires pouvant perdurer pendant plusieurs mois. Plusieurs expérimentations ont été menées in situ, et montrent que les fragments de laminaires possèdent une dégradation particulièrement lente comparée aux autres macroalgues brunes. Au cours de la dégradation, les fragments ont la capacité de maintenir plusieurs mois leur photosynthèse et potentiellement leur reproduction. Une communauté abondante de macrofaune (170 espèces identifiées) colonise les tissus et une succession écologique s’opère. L’étude du réseau trophique par l’analyse des isotopes stables (13C et 15N, naturels et enrichis artificiellement) révèle que les fragments de L. hyperborea contribuent significativement au régime alimentaire de l’ensemble des espèces (herbivores, détritivores, omnivores, filtreurs et prédateurs). Les forêts à L. hyperborea jouent ainsi un rôle écologique important pour un grand nombre d’écosystèmes côtiers où les fragments sont exportés et leur aire d’influence sur les milieux côtiers est très probablement sous-estimée.
... Although the impacts of global change on these coastal systems are multiple, much research has focused on the study of changes in abundance and distribution of species directly related to temperature (Harley et al., 2006(Harley et al., , 2012. The intertidal fucacean have been an exceptional study model because they have undergone remarkable changes in their distribution ranges shifting polewards and decrease in their population densities coinciding with the increase of the temperature of the ocean (Duarte et al., 2013;Jueterbock et al., 2013;Nicastro et al., 2013;Straub et al., 2016). In addition, the main environmental characteristic of the intertidal zone is the regular exposure to atmospheric conditions, with more extreme temperature regimes than in the sublittoral (Hawkins et al., 2016). ...
... F. guiryi populations located in the northern and southern slopes of the island, showed signs of decline over the last fifty years, although these changes were statistically significant only in the southern populations. Long-term monitoring and models of future projections have demonstrated or predicted a generalized retraction to polewards in many habitat-forming temperate macroalgae (Jueterbock et al., 2013;Straub et al., 2016;Martínez et al., 2018). Previous studies showed that F. guiryi have followed a stronger decline in its populations on the western islands of the Canarian archipelago compared to the eastern ones, related to the gradient in oceanographic conditions (Riera et al., 2015). ...
Fucus guiryi is a species strongly threatened by climate change, and the populations in its southern distribution limit
are fast disappearing. However, the extinction of this species is not widespread, since there are small places where
some populations still survive. In this study we explore the general regression trend of F. guiryi populations in Tenerife
(Canary Islands), and compare the changes in the thallus morphology, density of individuals and biomass that have
occurred in two of its populations over the last decades. Our results show that populations on the North and South of
the island have followed different trajectories. Populations of F. guiryi in the North showed a slight regression, the
thallus still have a similar size to the past and have numerous receptacles. On the contrary, those of the South are in a
critical state, with a strong reduction in plant size and loss of reproductive capacity. The biomass of the southern
populations has also been reduced by 90%. The increase in wind speed, sea surface temperature and air temperature
were negatively related to the development of F. guiryi populations. Our results suggest a ‘site effect’, where the
geography and local climatic conditions interact with the current global warming trend. In this sense, some places in
the North of the island, with climatic conditions less adverse to F. guiryi growth, are acting as refugia.
... fragile (reported as C. fragile subsp. tomentosoides); and the red algae Acanthophora spicifera, Gracilaria vermiculophylla, Grateloupia lanceolate and G. turuturu (Pedroche and Sentíes 2003, Bellorin et al. 2004, Wilkinson et al. 2009, Ávila et al. 2012, Aguilar-Rosas et al. 2013, Straub et al. 2016). ...
High diversity of marine macroalgae is reported for Mexican coasts, including numerous endemic species. Seaweed research in Mexico has focused on the northern regions of the Pacific coast (Temperate Pacific and Gulf of California) and on the Mexican Caribbean coast, leaving aside other regions (Tropical Pacific and Gulf of Mexico). Utilization of seaweed resources within the country has been based on artisanal collection of wild populations mainly for polysaccharide extraction, fertilizers, raw material for animal feed and cosmetic products. The main exploitation has occurred along the coasts of Baja California peninsula, based on few species ( Gelidium robustum , Macrocystis pyrifera , Chondracanthus canaliculatus and Gracilariopsis lemaneiformis ). Governmental regulations for management have allowed harvesting to reach approximately 11,500 wet tons per year (2013–2016). Nevertheless, in recent years (2014–2016) the total seaweed import volume has increased (5302 tons per year in average) over the export volume (2156 tons per year in average), suggesting a notably growing demand for seaweed resources in the country and representing an opportunity for investment projects. Several pilot studies on seaweed cultivation in Mexico propose that sustainable aquaculture techniques could complement the harvest in natural populations and ensure a homogeneous production with high quality in the long term.
