Government s. Organization s. Although these species occur in the Gulf of Mexico and Caribbean, the extent of their occurrence in the Sargasso Sea provides a unique and valuable structurally complex habitat in deep, open- ocean waters. Here, the areal extent of the Sargassum and the thickness of the mats it forms, along with their persistence, attract and retain a great density and diversity of associated organisms, distinguishing the Sargasso Sea ecosystem from other drift algal habitats Stoner and Greening , Coston-Clements et al , Moser et al , Casazza and Ross The Sargasso Sea is also the northerly limit of persistent Sargassum presence.
The Sargasso Sea is home to numerous endemic species that are, by definition, rare. The mid-water fish community of the Sargasso Sea includes a suite of sub-tropical endemics from three genera in the family Stomiidae Porteiro On the sea floor, the New England seamount chain and the Corner Sea Rise seamounts are known to host endemic species and specialised communities, and models indicate that other isolated seamounts occur throughout the area Figure 1.
Justification The Sargasso Sea is of considerable international importance as the only spawning area for American and European eels, Anguilla rostrata and A. Both species spend their adult lives in freshwater but migrate thousands of miles to the Sargasso Sea to spawn Schmidt , Kleckner et al , Friedland et al The larvae of both species develop in the Sargasso Sea and migrate along the Gulf Stream back to their respective freshwater habitats in North America and Europe.
Satellite tagging has also recently shown that large female porbeagle sharks Lamna nasus migrate over 2, km at depths of up to m from Canadian waters to the Sargasso Sea, where they may be pupping Dulvy et al , Campana et al The Sargassum anglerfish Histrio histrio and pipefish Syngnathus pelagicus lay their eggs in the Sargassum mats, and oceanic flying fish Exocoetidae build bubble nests for their eggs within the weed and have eggs with long extensions for attaching to the weed Dooley , Sterrer The Corner Rise and New England Seamounts host abundant populations of deep-water fish and, despite heavy commercial exploitation, remain important as aggregating and spawning areas for the alfonsino Beryx splendens.
The mats of Sargassum and their associated communities are essential as nursery habitats and feeding areas for many species of fish, seabirds, and turtles. Fish living within the Sargassum canopy include juvenile swordfish Xiphius gladius , juvenile and sub-adult jacks Carangidae , juvenile and sub-adult dolphinfish Coryphaenidae , filefish and triggerfish Balistidae of all life stages, and driftfish Stromateidae Fedoryako , Coston-Clements et al , South Atlantic Fishery Management Council , Casazza and Ross , Rudershausen et al These fish are in turn a food resource for larger predatory species.
The Sargasso Sea provides critical food and shelter for a variety of organisms on migratory routes between the tropical and temperate Atlantic.
Basking sharks Cetorhinus maximus make regular seasonal movements to the Sargasso Sea during winter months at depths of m metres Skomal et al Adult leatherback turtles Dermochelys coriacea migrate north through the Sargasso Sea from nesting sites in the Caribbean Sea Ferraroli et al , Hays et al , and seasonally to the Sargasso Sea from foraging locations in coastal waters of New England and Nova Scotia James et al Humpback whales Megaptera novaeangliae pass through the Sargasso Sea during their annual migrations between the Caribbean and the northern North Atlantic Martin et al , Stone et al , G.
The same individuals are seen year after year off Bermuda and further north in the Stellwagen Bank Marine Sanctuary off the east coast of the USA Stevenson , unpub.
Some 30 cetacean species live in or migrate through the Sargasso Sea, as do several species of endangered or threatened tuna and sharks. Leatherback turtles also migrate through the area. The distinct seamount communities are rare habitats that are home to a variety of endemic species with very limited distribution that are thus at high risk of extinction.
Threatened and endangered species utilising the Sargasso Sea include seabirds in the air above, turtles in the floating Sargassum, large pelagic fishes and cetaceans in the waters below, and a wide variety of corals on seamounts rising from the seabed. Justification Deep-sea organisms and their communities are considered extremely vulnerable because such species are generally long-lived, slow to mature and have low reproductive rates, leading to slow recovery times if their populations are perturbed Norse et al In addition, many organisms in the deep sea are physically fragile and easily damaged.
The benthic communities on seamounts are particularly vulnerable as they may be isolated from external sources of replenishment and they often contain endemic species with very limited distributions.
Within this area meeting EBSA criteria, the Corner Rise, New England and Muir seamount chains support complex coral and sponge communities, including numerous endemics, which provide habitat for diverse invertebrate communities that include some highly dependent commensal species , Watling et al , Cho , Simpson and Watling , Pante and Watling , ICES , Shank These seamounts also host abundant populations of deep-water fish.
Deep-sea and seamount fish stocks are particularly vulnerable to exploitation because the fish are very long-lived, take many years to reach sexual maturity, and have very low fecundities Norse et al These fish stocks have been heavily exploited commercially since Vinnichenko , and the fragile seamount ecosystems of the Corner Rise and New England chains have already sustained considered damage from these deep-sea trawling activities.
Nevertheless, the seamounts remain important as aggregating and spawning areas for the alfonsino Beryx splendens. The communities dependent on the Sargassum mats are also vulnerable, although to a lesser degree, as their existence relies on the presence of the complex physical structure provided by the seaweed. Justification The discovery of Prochlorococcus and the development of techniques able to evaluate the role of picoplankton in primary production measurements have revolutionized our perceptions of productivity in the Sargasso Sea and subsequently of the global ocean Chisholm et al Conventionally the Sargasso Sea was regarded as an area of low nutrients and low productivity, enhanced by localized upwellings.
Yet despite having low nutrient levels and therefore being officially classed as oligotrophic, the Sargasso Sea, per unit area, has a surprisingly high net annual primary production rate that matches levels found in some of the most productive regions in the global ocean Steinberg et al , Rho and Whitledge , Lomas et al This is due to a complex combination of factors—the production of carbon in the surface waters by photosynthesis, the location of the Sargasso Sea in the sub-tropics which results in a deep euphotic layer, and differences in phytoplankton communities and associated nitrogen fixation.
The difference is that in the Sargasso Sea most of the production is recycled by bacteria in the so-called microbial loop rather than channelled into biomass of larger, harvestable organisms Carlson et al , Steinberg et al As a result of this high primary productivity, to which must be added the annual production of Sargassum weed, which is now being estimated from satellite measurements Gower and King , , the Sargasso Sea plays a key role in both global oxygen production and ocean sequestration of carbon IPCC, and , Ullman et al , Lomas et al unpub.
Justification The biodiversity of the Sargasso Sea is exemplified by the diverse population of species that live on or amongst the Sargassum. More than species of invertebrates have been recorded, including a variety of gastropod and nudibranch molluscs, portunid and amphipod crustaceans, pycnogonids, serpulid and nereid polychaetes, flatworms, bryozoans and hydroids Fine , Morris and Mogelberg , Butler et al , Coston-Clements et al , Sterrer , Calder , South Atlantic Fishery Management Council , Trott et al In addition, over species of fish associate with floating Sargassum offshore Dooley , Fedoryako , Coston-Clements et al , Casazza and Ross , Sutton et al Most of these species would not live in the open ocean without the floating algae.
Ten of these species are endemic to floating Sargassum: the Sargassum anglerfish Histrio histrio , Sargassum pipefish Syngnathus pelagicus , Sargassum slug Scyllea pelagica , Sargassum snail Litiopa melanostoma , Sargassum crab Planes minutes , Sargassum shrimp Latreutes fucorum , the amphipods Sunampithoe pelagica and Biancolina brassicacephala, the platyhelminth Hoploplana grubei and the Sargassum anemone Anemonia sargassensis.
The diversity of oceanic plankton and micronekton within the Sargasso Sea is enhanced as species are drawn in from the surrounding currents via rings and eddies Boyd et al , Wiebe and Boyd , Ring Group Overall, mesopelagic diversity is not considered to be higher than other similar locations, but a variety of species from a wide range of taxa have been documented from this deeper part of the ocean.
A study of the bathypelagic fish family Stomiidae found a suite of sub-tropical endemic species in the northern Sargasso Sea, primarily from the genus Eustomias but also in the genera Photonectes and Bathophilus, and determined that the area exhibited higher levels of endemicity for this group than other North Atlantic biogeographic provinces Porteiro The ostracods are likely to be an indicator of the potential numbers of new species yet to be discovered in the deep ocean.
Benthic diversity is very high on the Corner Rise and New England seamount chains, where there are numerous endemic and novel species of coral that host specific commensal invertebrates, and some species have been found Watling , Watling et al , Cho , Simpson and Watling , Pante and Watling , ICES , Shank Less is known about the Muir seamount chain, but limited observations have shown it is covered with abundant hydroids, sponges, calcareous algae and rubble Pratt Justification Despite its remote location, the Sargasso Sea does not remain totally natural.
Deep pelagic and bottom trawling between and on the Corner Rise seamounts caused extensive destruction of the benthic fauna Vinnichenko, , Waller et al , Shank As a precautionary management measure, 13 fishable seamounts, including 25 peaks shallower than 2, m on the New England and Corner Rise seamounts were closed to demersal fishing by the Northwest Atlantic Fishery Organization NAFO] from 1 January Floating plastic particles were reported in the Sargasso Sea as early as Carpenter and Smith , and today the North Atlantic gyre has a patch of floating debris akin to the more famous North Pacific garbage patch with concentrations of plastic particles reaching in excess of , pieces km-2 in some places Law et al This clearly impacts the naturalness of the area, and the negative impacts of plastic debris on organisms such as turtles and seabirds, are well documented Witherington , Rios et al There are also numerous submarine communications cables that have a minor effect on the naturalness of the seabed Telegeography This affects the naturalness of the area, but precise impacts are unclear as appropriate research is lacking GESAMP and this absence of data should be addressed.
The Sargassum mats and windrows provide shelter and nutrients for a wide variety of species, some endemic and some endangered, like sea turtles, as well as a number of commercially important species like billfish and tunas. It is also on the migration route of many species, including sharks and cetaceans. It is also thought to be the only place in the world where the critically endangered catadromous European eel Anguilla anguilla and endangered American eel A.
Surrounding the archipelago of Bermuda and within the area of the Sargasso Sea lies an abyssal plain some 4, metres deep, with three groups of seamounts that are 70 to 90 million years old: the New England and the Corner Rise seamounts to the north, and to the east the Mid-Atlantic Ridge Seamounts Freestone and Bulger, Since there have been regular mass strandings of thousands of tons of Sargassum on beaches within the Caribbean, Gulf of Mexico and the coasts of West Africa and South America Freestone et al.
The blooms were identified as a previously rare form of Sargassum S. It differs morphologically from both S. Consequently, changes in Sargassum type or distribution could impact species diversity and abundance.
So far, these blooms have not impacted the Sargasso Sea directly but they have the potential to do so via reduced Sargassum communities and because they are preventing successful nesting of turtles on the affected beaches around the Caribbean Johnson et al.
In October the newly established Commission met with the Government Signatories to the Declaration and together they agreed six priority areas for its first 2 year work program Freestone and Bulger, These priority areas are each discussed below, although not in any order of importance. The Commission has continued to leverage this description in other fora Freestone and Morrison, The Sargasso Sea was the only named ecosystem with a separate chapter in that report Freestone et al.
That chapter was updated in the Second Assessment in Roe et al. The Commission has also established a network of bilateral links with key organizations with related competencies or similar objectives. In total, the Commission also has more than 30 formal Collaborating Partners envisaged by paragraph 11 of the Hamilton Declaration , as well as a number of Programmatic Partners.
More than fifteen dedicated major research papers have been contributed to the ecosystem subcommittee of the Standing Committee on Research and Statistics SCRS or the Science Body , and the government of Bermuda—with Commission support—has proposed two resolutions relating to the Sargasso Sea, both of which were adopted after some amendment in the Commission plenary sessions ICCAT, In September , after the CBD EBSA description, the NAFO Scientific Council was formally asked, on behalf the Sargasso Sea project, to comment and advise on whether the Sargasso Sea provides forage area or habitat for living marine resources that could be impacted by different types of fishing, and on whether there is a need for any closure to protect this ecosystem.
Some considerable interest was generated by these events. The Commission is still considering the possibility of making proposals to IMO in relation to shipping activities in the Sargasso Sea.
At various point in their respective life cycles, a number of migratory species pass through the Sargasso Sea and make use of it. The young turtles in particular use Sargassum weed for cover, feeding and nursery habitat. In the Secretariats collaborated on the development of a joint information paper on the crucial significance of Sargassum and the Sargasso Sea for Atlantic sea turtles. That short paper demonstrated how important the migration links between Bermuda and the Sargasso Sea and many of the Central American countries were for sea turtles SSC, In , the government of the Principality of Monaco in its capacity as a signatory to the Hamilton Declaration put forward the report on behalf of the Commission.
At the request of DFO in , it will organize a virtual workshop of those range States with significant American eel fisheries to develop a future plan of action for collaboration. The Commission, assisted by key marine researchers and scientists, is also involved in an invaluable collaboration with the US National Aeronautics and Space Administration NASA aimed at developing a multidimensional mapping tool.
This tool will use the Sargasso Sea as a pilot area. COVERAGE seeks to provide improved, more seamless access to inter-agency, multivariate satellite data spanning the four CEOS Ocean Virtual Constellations—sea surface temperature, ocean vector winds, ocean surface topography, ocean color radiometry—in support of a priority set of application use cases identified by stakeholders.
It additionally seeks to demonstrate a technical framework facilitating more synergistic use of remote sensing and in situ data for the oceans from distributed sources. This project is designed to permit users to access and visually display relevant data of their choosing.
These data can combine NASA satellite observation data of oceanographic conditions, such as currents, temperature, salinity, chlorophyll as well as possibly seaweed presence and movement, with data form other sources on commercial, recreational, ecological and biological uses of the sea. The expectation is that this important project will provide an important tool with considerable future potential for high seas conservation and governance.
As can be seen, it was deliberately designed to be different from existing treaty regimes with which it has inevitably been compared Freestone et al. One of the basic principles adopted by the Sargasso Sea project has been to base its proposals and approaches on the best available science. In it sponsored the production, and publication in a research series, of some 12 specialized reports that collected the latest scientific information on a full range of Sargasso Sea ecosystem issues, from oceanography to seabed resources, from whale migration to eels and eel spawning.
These constituted the foundation for a full scale baseline science study published in This study had some fifty contributors and carried the logos of 10 leading marine science institutions from Europe and the Americas Laffoley et al. The Commission has continued to be able to draw on the wide spread of expertise in key partners from many different disciplines—many of them now among the thirty or more formal Collaborating Partners of the Commission.
In it was suggested that. In the context of the work on the Sargasso Sea, the discussion above may already have highlighted the preeminent role of science in the work of the Commission, but a couple of examples may illustrate the way the Hamilton Declaration design is intended to function.
As part of the preparations for the Sargasso Sea baseline study in , a series of detailed scientific reports were also commissioned and published on the website. One of these related to the European eel Gollock, It was clear from this that the state of the stock met the criteria for listing under Appendix II of the Convention on Migratory Species and, as discussed above, Monaco—one of the Signatory States which is an active party to CMS—put that proposal forward.
So it was the scientific work which prompted the legal action. As a follow on to that process the Commission has organized and financed, with partners, some five workshops for American and European Eel Range States representatives and scientists. It is likely that policy proposals for future conservation measures will result from that work—which is ongoing. The Commission has sponsored basic science research including the preparation of a pelagic food web analysis for tuna and non-tuna species Luckhurst, , , ; Luckhurst and Arocha, For the last decade the UN has been discussing the idea of a new international agreement linked to the LOSC on the conservation and sustainable use of biological diversity in areas beyond national jurisdiction; since an Inter-Governmental Conference IGC has been negotiating such an instrument Freestone, The lessons learned from the Sargasso Sea project have demonstrated many of the problems and limitations of working within the existing sectoral and fragmented system of ocean governance Freestone and Gjerde, Despite the plethora of international organisations with an interest in ABNJ, there are only a handful with actual management competence in the Sargasso Sea area and none with a core focus on comprehensive conservation of marine biodiversity or ecosystems.
The Sargasso Sea project thus provides an interesting insight into the way in which the current system of high seas governance operates. Each sectoral regime with competence over activities in the Sargasso Sea study area has its own distinctive protection mechanisms and each assesses differently the factors that need to be taken into account. The result is a patchwork of sectoral area-based management tools designed to protect specific marine areas from sectorally specific threats.
Each of these sectoral approaches has value, but each is developed and assessed by its own criteria and scientific evidentiary demands. None were developed with any reference to the work of other sectoral bodies and no mechanism exists for coordinating between the various sectors.
Moreover, regulation within sectors may be inconsistent both globally and regionally. For example, global criteria and guidelines exist to put biodiversity conservation squarely on the agenda of RFMOs such as NAFO responsible for managing deep sea bottom fishing on the high seas, but no such criteria or guidelines exist for other forms of fishing, despite the potential for significant biodiversity impacts.
On top of this, there is no mechanism for consideration of cumulative impacts from different sectors or the aggravating factor of climate change Freestone and Gjerde, It is also clear from the efforts of the Sargasso Sea project that there is considerable reluctance among key sectoral regulatory organizations to put into practice a number of important principles that are in major international legal and policy instruments—including the ecosystem approach and the precautionary approach.
Despite the widespread acceptance of the precautionary approach in many international instruments relating to the marine environment Freestone, there is still obvious reluctance to apply a precautionary approach in relation to activities on the high seas, despite that fact that precaution is particularly appropriate in these areas because scientific evidence is often scanty.
This suggestion in the guidelines is in practice, treated as if is it an evidentiary requirement by many influential delegations at IMO. Sargassum is a brown algae that forms a unique and highly productive floating ecosystem on the surface of the open ocean. The Sargasso Sea is a vast patch of ocean named for a genus of free-floating seaweed called Sargassum.
While there are many different types of algae found floating in the ocean all around world, the Sargasso Sea is unique in that it harbors species of sargassum that are 'holopelagic' — this means that the algae not only freely floats around the ocean, but it reproduces vegetatively on the high seas. Other seaweeds reproduce and begin life on the floor of the ocean. Wed, 12 Mar Photo: Don Kincaid. Photo: Abundance of life in the Sargasso Sea. Prev Next. Work area:.
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