Lophelia

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Lophelia
Lophelia spec.jpg
CITES Appendix II (CITES)
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Cnidaria
Class: Hexacorallia
Order: Scleractinia
Family: Caryophylliidae
Genus: Lophelia
Milne-Edwards & Haime, 1849
Species:
L. pertusa
Binomial name
Lophelia pertusa
Lophelia worldmap 372.jpg
Known range (NOAA)
Synonyms   [1]
  • Dendrosmilia nomlandiDurham & Barnard, 1952
  • Lophelia californicaDurham, 1947
  • Lophelia prolifera(Pallas, 1766)
  • Lophohelia affinisPourtalès, 1868
  • Lophohelia prolifera
  • Lophohelia prolifera f. brachycephalaMoseley, 1881
  • Lophohelia prolifera f. gracilisDuncan, 1873
  • Lophohelia subcostataMilne-Edwards & Haime, 1850
  • Lophohelia tubulosaStuder, 1878
  • Madrepora pertusaLinnaeus, 1758
  • Madrepora proliferaPallas, 1766

Lophelia pertusa, the only species in the genus Lophelia, [2] [3] is a cold-water coral that grows in the deep waters throughout the North Atlantic ocean, as well as parts of the Caribbean Sea and Alboran Sea. [4] Although L. pertusa reefs are home to a diverse community, the species is extremely slow growing and may be harmed by destructive fishing practices, or oil exploration and extraction. [5]

Contents

Biology

Lophelia pertusa Lophelia figure 1 600.jpg
Lophelia pertusa

Lophelia pertusa is a reef building, deep water coral, but it does not contain zooxanthellae, the symbiotic algae which lives inside most tropical reef building corals. [6] Lophelia lives at a temperature range from about 4–12 °C (39–54 °F) and at depths between 80 metres (260 ft) and over 3,000 metres (9,800 ft), but most commonly at depths of 200–1,000 metres (660–3,280 ft), where there is no sunlight. [7]

As a coral, it represents a colonial organism, which consists of many individuals. New polyps live and build upon the calcium carbonate skeletal remains of previous generations. Living coral ranges in colour from white to orange-red; each polyp has up to 16 tentacles and is a translucent pink, yellow or white. Unlike most tropical corals, the polyps are not interconnected by living tissue. Some colonies have larger polyps while others have small and delicate -looking ones. [7] Radiocarbon dating indicates that some Lophelia reefs in the waters off North Carolina may be 40,000 years old, with individual living coral bushes as much as 1,000 years old.

The colony grows by budding new polyps, with living ones emerging around the outer edges of deceased coral. Coral colonies reproduce asexually through fragmentation. Each colony is gendered, engaging in sexual reproduction by releasing sperm or oocytes into the sea. The larvae, which do not feed but rely on their yolk reserves, drift with plankton for weeks. Upon settling on the seabed, they undergo metamorphosis, developing into polyps capable of initiating new colonies. [7]

New polyps grow on the outer edges when Lophelia pertusa experiences budding or regeneration. Lophelia pertusa NOAA.jpg
New polyps grow on the outer edges when Lophelia pertusa experiences budding or regeneration.

Lophelia reefs can grow to 35 m (115 ft) high. The largest recorded Lophelia reef, Røst Reef, measures 3 km × 35 km (1.9 mi × 21.7 mi) and lies at a depth of 300–400 m (980–1,310 ft) off the Lofoten Islands, Norway. [8] These reefs are ancient, with a growth rate of around 1 mm per year.

Polyps at the end of branches feed by extending their tentacles and straining plankton from the seawater. They are able to ingest particles of up to 2 cm, and are able to discriminate between food and sediment using their chemoreceptors to differentiate between the two. Growth of polyps depends on environmental factors such as food availability, water quality, and how the water flows. [9]

L. pertusa are considered to be opportunistic feeders since they feed on particles of organic matter that have been broken down. [10] Hence, the spring bloom of phytoplankton and subsequent zooplankton blooms provide the main source of nutrient input to the deep sea. This rain of dead plankton is visible on photographs of the seabed and stimulates a seasonal cycle of growth and reproduction in Lophelia. This cycle is recorded in patterns of growth, and can be studied to investigate climatic variation in the recent past.

Conservation status

L. pertusa was listed under CITES Appendix II in January 1990, meaning that the United Nations Environmental Programme recognizes that this species is not necessarily currently threatened with extinction but that it may become so in the future. CITES is a means of restricting international trade in endangered species, which is not a major threat to the survival of L. pertusa. The OSPAR Commission for the protection of the marine environment of the North-East Atlantic have recognized Lophelia pertusa reefs as a threatened habitat in need of protection. [5]

The primary threats arise from the devastation of reefs caused by the use of heavy deep-sea trawl nets, specifically aimed at catching redfish or grenadiers. These nets, equipped with heavy metal "doors" to keep the net open, and a "footline" fitted with large metal "rollers," are dragged across the seabed, inflicting severe damage on coral. Given the slow growth rate of coral, this practice is unlikely to be sustainable in the long term.

A squat lobster living on a Lophelia reef Lophelia fauna 600.jpg
A squat lobster living on a Lophelia reef

Scientists estimate that trawling has damaged or destroyed 30%–50% of the Norwegian shelf coral area. The International Council for the Exploration of the Sea, the European Commission’s main scientific advisor on fisheries and environmental issues in the northeast Atlantic, recommend mapping and then closing all of Europe’s deep corals to fishing trawlers. [11]

In 1999, the Norwegian Ministry of Fisheries closed an area of 1,000 square kilometres (390 sq mi) at Sula, including the large reef, to bottom trawling. In 2000, an additional area closed, covering about 600 square kilometres (230 sq mi). An area of about 300 square kilometres (120 sq mi) enclosing the Røst Reef closed to bottom trawling in 2002. [11] Bottom trawling leads to siltation or sand deposition, which involves the disturbance of underlying sediments and nutrients. This harmful process destroys and decreases the growth of coral reefs, affecting the expansion of polyp budding. [12]

In recent years, environmental organizations such as Greenpeace have argued that exploration for oil on the north west continental shelf slopes of Europe should be curtailed due to the possibility that is it damaging to the Lophelia reefs - conversely, Lophelia has recently been observed growing on the legs of oil installations, [13] specifically the Brent Spar rig which Greenpeace campaigned to remove. At the time, the growth of L. pertusa on the legs of oil rigs was considered unusual, [14] although recent studies have shown this to be a common occurrence, with 13 of 14 North Sea oil rigs examined having L. pertusa colonies. [15] The authors of the original work suggested that it may be better to leave the lower parts of such structures in place— a suggestion opposed by Greenpeace campaigner Simon Reddy, who compared it to "[dumping] a car in a wood – moss would grow on it, and if I was lucky a bird may even nest in it. But this is not justification to fill our forests with disused cars". [16]

Recovery of damaged L.pertusa will be a slow process not only due to its slow growth rate, but also due to its low rates of colonization and recolonization process. This is because even if L.pertusa produces a dispersive larva, a sediment free surface is required to initiate a new settlement. Moreover, excessive sedimentation and chemical contaminants will negatively impact the larvae, even when they are available in large numbers. [17]

As ocean temperatures continue to rise due to global warming, climate change is another deadly factor that threatens the existence of L. pertusa. Although L. pertusa can survive changes in oxygen levels during periods of hypoxia and anoxia, they are vulnerable to sudden temperature changes. These fluctuations in temperature affect their metabolic rate, which has detrimental consequences regarding their energy input and growth. [18]

Ecological significance

L. pertusa in its ecological environment. Expl0006 - Flickr - NOAA Photo Library.jpg
L. pertusa in its ecological environment.

Lophelia beds create a specialized habitat favored by some species of deep water fishes. Surveys have recorded that conger eels, sharks, groupers, hake and the invertebrate community consisting of brittle stars, molluscs, amphipods and crabs reside on these beds. High densities of smaller fish such as hatchetfish and lanternfish have been recorded in the waters over Lophelia beds, indicating they may be important prey items for the larger fish below.

L. pertusa also forms a symbiosis with polychaete Eunice norvegica. It is suggested that E. norvegica positively influences L.pertusa by forming connecting tubes, which are later calcified, in order to strengthen the reef frameworks. While E. norvegica requires partial consumption of the food obtained by L. pertusa, E. norvegica aids in cleaning the living coral framework and protecting it from potential predators. [19]

Foraminiferans including Hyrrokkin sarcophaga also carry out a parasitic relationship with L. pertusa by attaching to polyps on the coral. Although settlement and reproduction are carried out by H. sarchophaga, this parasitism is not detrimental to the coral. [9]

Range

L. pertusa has been reported from Anguilla, Bahamas, Bermuda, Brazil, Canada, Cape Verde, Colombia, Cuba, Cyprus, Ecuador, Faroe Islands, France, French Southern Territories, Greece, Grenada, Iceland, India, Ireland, Italy, Jamaica, Japan, Madagascar, Mexico, Montserrat, Norway, Portugal, Puerto Rico, Saint Helena, Saint Kitts and Nevis, Saint Vincent and the Grenadines, Senegal, South Africa, United Kingdom, United States of America, U.S. Virgin Islands and Wallis and Futuna Islands. [20]

Related Research Articles

<span class="mw-page-title-main">Coral</span> Marine invertebrates of the class Anthozoa

Corals are colonial marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.

<span class="mw-page-title-main">Coral reef</span> Outcrop of rock in the sea formed by the growth and deposit of stony coral skeletons

A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups.

Darwin Mounds is a large field of undersea sand mounds situated off the north west coast of Scotland that were first discovered in May 1998. They provide a unique habitat for ancient deep water coral reefs and were found using remote sensing techniques during surveys funded by the oil industry and steered by the joint industry and United Kingdom government group the Atlantic Frontier Environment Network (AFEN). The mounds were named after the research vessel, itself named for the eminent naturalist and evolutionary theorist Charles Darwin.

<span class="mw-page-title-main">Anthozoa</span> Class of cnidarians without a medusa stage

Anthozoa is a class of marine invertebrates which includes the sea anemones, stony corals and soft corals. Adult anthozoans are almost all attached to the seabed, while their larvae can disperse as part of the plankton. The basic unit of the adult is the polyp; this consists of a cylindrical column topped by a disc with a central mouth surrounded by tentacles. Sea anemones are mostly solitary, but the majority of corals are colonial, being formed by the budding of new polyps from an original, founding individual. Colonies are strengthened by calcium carbonate and other materials and take various massive, plate-like, bushy or leafy forms.

<span class="mw-page-title-main">Scleractinia</span> Order of Hexacorallia which produce a massive stony skeleton

Scleractinia, also called stony corals or hard corals, are marine animals in the phylum Cnidaria that build themselves a hard skeleton. The individual animals are known as polyps and have a cylindrical body crowned by an oral disc in which a mouth is fringed with tentacles. Although some species are solitary, most are colonial. The founding polyp settles and starts to secrete calcium carbonate to protect its soft body. Solitary corals can be as much as 25 cm (10 in) across but in colonial species the polyps are usually only a few millimetres in diameter. These polyps reproduce asexually by budding, but remain attached to each other, forming a multi-polyp colony of clones with a common skeleton, which may be up to several metres in diameter or height according to species.

<span class="mw-page-title-main">Alcyonacea</span> Order of octocorals that do not produce massive calcium carbonate skeletons

Alcyonacea are a species of sessile colonial cnidarians that are found throughout the oceans of the world, especially in the deep sea, polar waters, tropics and subtropics. Whilst not in a strict taxonomic sense, Alcyonacea are commonly known as "soft corals" (Octocorallia) that are quite different from "true" corals (Scleractinia). The term “soft coral” generally applies to organisms in the two orders Pennatulacea and Alcyonacea with their polyps embedded within a fleshy mass of coenenchymal tissue. Consequently, the term “gorgonian coral” is commonly handed to multiple species in the order Alcyonacea that produce a mineralized skeletal axis composed of calcite and the proteinaceous material gorgonin only and corresponds to only one of several families within the formally accepted taxon Gorgoniidae (Scleractinia). These can be found in order Malacalcyonacea (taxonomic synonyms of include : Alcyoniina, Holaxonia, Protoalcyonaria, Scleraxonia, and Stolonifera. They are sessile colonial cnidarians that are found throughout the oceans of the world, especially in the deep sea, polar waters, tropics and subtropics. Common names for subsets of this order are sea fans and sea whips; others are similar to the sea pens of related order Pennatulacea. Individual tiny polyps form colonies that are normally erect, flattened, branching, and reminiscent of a fan. Others may be whiplike, bushy, or even encrusting. A colony can be several feet high and across, but only a few inches thick. They may be brightly coloured, often purple, red, or yellow. Photosynthetic gorgonians can be successfully kept in captive aquaria.

<span class="mw-page-title-main">Ivory bush coral</span> Species of cnidarian

Oculina varicosa, or the ivory bush coral, is a scleractinian deep-water coral primarily found at depths of 70-100m, and ranges from Bermuda and Cape Hatteras to the Gulf of Mexico and the Caribbean. Oculina varicosa flourishes at the Oculina Bank off the east coast of Florida, where coral thickets house a variety of marine organisms. The U.S. National Marine Fisheries Service considers Oculina a genus of concern, due to the threat of rapid ocean warming. Species of concern are those species about which the U.S. Government's National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service, has some concerns regarding status and threats, but for which insufficient information is available to indicate a need to list the species under the U.S. Endangered Species Act (ESA). While Oculina is considered a more robust genus in comparison to tropical corals, rising ocean temperatures continue to threaten coral health across the planet.

<span class="mw-page-title-main">Deep-water coral</span>

The habitat of deep-water corals, also known as cold-water corals, extends to deeper, darker parts of the oceans than tropical corals, ranging from near the surface to the abyss, beyond 2,000 metres (6,600 ft) where water temperatures may be as cold as 4 °C (39 °F). Deep-water corals belong to the Phylum Cnidaria and are most often stony corals, but also include black and thorny corals and soft corals including the Gorgonians. Like tropical corals, they provide habitat to other species, but deep-water corals do not require zooxanthellae to survive.

<i>Madrepora oculata</i> Species of coral

Madrepora oculata, also called zigzag coral, is a stony coral that is found worldwide outside of the polar regions, growing in deep water at depths of 80–1500 meters. It was first described by Carl Linnaeus in his landmark 1758 10th edition of Systema Naturae. It is one of only 12 species of coral that are found worldwide, including in Subantarctic oceans. In some areas, such as in the Mediterranean Sea and the North-east Atlantic Ocean, it dominates communities of coral.

<span class="mw-page-title-main">Hotspot Ecosystem Research and Man's Impact On European Seas</span> International multidisciplinary project that studies deep-sea ecosystems

Hotspot Ecosystem Research and Man's Impact On European Seas (HERMIONE) is an international multidisciplinary project, started in April 2009, that studies deep-sea ecosystems. HERMIONE scientists study the distribution of hotspot ecosystems, how they function and how they interconnect, partially in the context of how these ecosystems are being affected by climate change and impacted by humans through overfishing, resource extraction, seabed installations and pollution. Major aims of the project are to understand how humans are affecting the deep-sea environment and to provide policy makers with accurate scientific information, enabling effective management strategies to protect deep sea ecosystems. The HERMIONE project is funded by the European Commission's Seventh Framework Programme, and is the successor to the HERMES project, which concluded in March 2009.

<i>Eumunida picta</i> Species of crustacean

Eumunida picta is a species of squat lobster found in the deep sea. The species is strongly associated with reefs of Lophelia pertusa, a deep-water coral, and with methane seeps. It is abundant in the western Atlantic Ocean, where it is found from Massachusetts to Colombia.

<i>Porites lobata</i> Species of coral

Porites lobata, known by the common name lobe coral, is a species of stony coral in the family Poritidae. It is found growing on coral reefs in tropical parts of the Indian and Pacific Oceans.

<i>Scolymia</i> Genus of corals

Scolymia, commonly called scoly coral, is a genus of large-polyp stony corals (Scleractinia). These animals are believed date back to the Miocene with three extant species present in the eastern Atlantic Ocean.

<i>Diploria</i> Genus of corals

Diploria is a monotypic genus of massive reef building stony corals in the family Mussidae. It is represented by a single species, Diploria labyrinthiformis, commonly known as grooved brain coral and is found in the western Atlantic Ocean and Caribbean Sea. It has a familiar, maze-like appearance.

The Rost Reef is a deep-water coral reef off the coast of the Lofoten islands in Nordland county, Norway. The reef was discovered in 2002, about 100 kilometres (62 mi) west of the island of Røstlandet. It extends over a length of about 43 kilometers (27 mi), and has a width of up to 6.9 kilometers (4.3 mi). The reef is generated by the coral Lophelia pertusa, and is the world's largest known Lophelia reef. It is also the world's largest known deep-water coral reef. The authorities have introduced regulations to protect the reef against trawling. The temperature of the waters near the bottom of the Rost coral reef is 2 °C. WWF recognises the Røst Reef as a global natural heritage that merits protection through Marine Protected Area (MPA) status.

The Sula Reef is a deep-water coral reef off the coast of Trøndelag, Norway. It is located on the Sula Ridge, named after the island of Sula. The reef is generated by the coral Lophelia pertusa. It has a length of about 13 kilometers (8.1 mi), and is 700 meters (2,300 ft) wide. The thickness of the reef is up to 35 meters (115 ft). Until the discovery of the Røst Reef in 2002, the Sula Reef was the world's largest known Lophelia reef. The Sula Reef is closed to trawling.

<i>Paragorgia arborea</i> Species of coral

Paragorgia arborea is a species of coral in the family Paragorgiidae, commonly known as the bubblegum coral because of its bulbous branch tips. It mainly grows in depths between 200 and 1,300 metres at temperatures between 3 and 8 °C. It is found widespread in the Northern Atlantic Ocean and Northern Pacific Ocean on seamounts and knolls, and was first described by the Swedish naturalist Carl Linnaeus in 1758. P. arborea is a foundation species, providing a habitat for other species in deep sea coral ecosystems.

<span class="mw-page-title-main">Euphylliidae</span> Family of marine coral known as Euphylliidae

Euphylliidae are known as a family of polyped stony corals under the order Scleractinia.

Eunice norvegica is an aquatic polychaete worm found in deep water on the seabed of the northern Atlantic Ocean as well as in the Pacific and Indian Oceans. It is a tubeworm and is often associated with deep water corals.

<i>Manicina areolata</i> Species of coral

Manicina areolata, commonly known as rose coral, is a colonial species of stony coral. It occurs in shallow water in the West Atlantic Ocean and Caribbean Sea, sometimes as small solid heads and sometimes as unattached cone-shaped forms.

References

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  20. As reported by CITES and the UNEP, and as such, is incomplete, and affected by development of marine science in that country, and effort put into surveying for it.[ citation needed ]