Instruct: Given a question, retrieve documents that can help answer the question.
Query: How many species of kelp are there?
Kelps are large brown algae seaweeds that make up the order Laminariales. There are about 30 different genera.[3]
Kelp forests have been important to human existence for thousands of years. Indeed, many now theorise that the first colonisation of the Americas was due to fishing communities following the Pacific kelp forests during the last ice age. One theory contends that the kelp forests that would have stretched from northeast Asia to the American Pacific coast would have provided many benefits to ancient boaters. The kelp forests would have provided many sustenance opportunities, as well as acting as a type of buffer from rough water. Besides these benefits, researchers believe that the kelp forests might have helped early boaters navigate, acting as a type of "kelp highway". Theorists also suggest that the kelp forests would have helped these ancient colonists by providing a stable way of life and preventing them from having to adapt to new ecosystems and develop new survival methods even as they traveled thousands of miles. Modern economies are based on fisheries of kelp-associated species such as lobster and rockfish. Humans can also harvest kelp directly to feed aquaculture species such as abalone and to extract the compound alginic acid, which is used in products like toothpaste and antacids. Kelp forests are valued for recreational activities such as SCUBA diving and kayaking; the industries that support these sports represent one benefit related to the ecosystem and the enjoyment derived from these activities represents another. All of these are examples of ecosystem services provided specifically by kelp forests.
The AMB's crest crafted by local Haida artist "Giitsxaa" represents the unique joint management relationship. 
The AMB chose the sea otter and the sea urchin because of the creatures' significance in the history and tradition of the protected area and because of their ecological significance.
Populations of sea urchin, a kelp-grazing species, were once kept in check by sea otters, ensuring an abundance of kelp and species that depend upon kelp communities. With the extirpation of sea otters during the Maritime Fur Trade, the natural balance between species in the community was disturbed. As a result, the sea urchin population has increased dramatically over time and the health of kelp forests is threatened. The loss of the sea otter is a powerful reminder of the vulnerability of individual species and entire ecosystems.
Overfishing nearshore ecosystems leads to the degradation of kelp forests. Herbivores are released from their usual population regulation, leading to over-grazing of kelp and other algae. This can quickly result in barren landscapes where only a small number of species can thrive.[27][28] Other major factors which threaten kelp include marine pollution and the quality of water, climate changes and certain invasive species.[29]
The brown algae (singular: alga), comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Most brown algae live in marine environments, where they play an important role both as food and as habitat. For instance, "Macrocystis", a kelp of the order Laminariales, may reach 60 m (200 ft) in length and forms prominent underwater kelp forests. Kelp forests like these contain a high level of biodiversity. Another example is "Sargassum", which creates unique floating mats of seaweed in the tropical waters of the Sargasso Sea that serve as the habitats for many species. Many brown algae, such as members of the order Fucales, commonly grow along rocky seashores. Some members of the class, such as kelps, are used by humans as food.
Many facets of the interaction between sea otters and the human economy are not as immediately felt. Sea otters have been credited with contributing to the kelp harvesting industry via their well-known role in controlling sea urchin populations; kelp is used in the production of diverse food and pharmaceutical products. Although human divers harvest red sea urchins both for food and to protect the kelp, sea otters hunt more sea urchin species and are more consistently effective in controlling these populations. The health of the kelp forest ecosystem is significant in nurturing populations of fish, including commercially important fish species. In some areas, sea otters are popular tourist attractions, bringing visitors to local hotels, restaurants, and sea otter-watching expeditions.
Frequently considered an ecosystem engineer, kelp provides a physical substrate and habitat for kelp forest communities. In algae (Kingdom: Protista), the body of an individual organism is known as a thallus rather than as a plant (Kingdom: Plantae). The morphological structure of a kelp thallus is defined by three basic structural units:
In addition, many kelp species have pneumatocysts, or gas-filled bladders, usually located at the base of fronds near the stipe. These structures provide the necessary buoyancy for kelp to maintain an upright position in the water column.
The largest marine algae are kelp species, which include bull kelp ("Durvillaea antarctica"), which can reach over long and is thought to be the strongest kelp in the world. As many as 47 individual plants can live on , and they can grow at a day. Kelp that is broken off its anchor provides a valuable food source for many animals, as well as providing a method of oceanic dispersal for animals such as invertebrates to travel across the Southern Ocean by riding floating kelp.
This marine fish is distributed from Sonoma County, California, south to central Baja California. The climate is subtropical. It lives in coastal waters up to 42 meters deep, but usually not more than about 12 meters. Its habitat includes kelp beds and rocky seabeds. It commonly associates with several other species of rockfish in this habitat, but it is more closely associated with the kelp than the others. During the day it often rests on the kelp blades, sometimes upside down. The main kelp species is "Macrocystis pyrifera", the giant kelp. Other brown algaes in the habitat can include "Pterygophora californica", "Cystoseira osmundacea", and species of "Desmarestia". It is also known from artificial habitat types, such as oil rigs.
Frequently considered an ecosystem engineer, kelp provides a physical substrate and habitat for kelp forest communities. In algae (kingdom Protista), the body of an individual organism is known as a thallus rather than as a plant (kingdom Plantae). The morphological structure of a kelp thallus is defined by three basic structural units:
In addition, many kelp species have pneumatocysts, or gas-filled bladders, usually located at the base of fronds near the stipe. These structures provide the necessary buoyancy for kelp to maintain an upright position in the water column.
In many places, managers have opted to regulate the harvest of kelp and/or the taking of kelp forest species by fisheries. While these may be effective in one sense, they do not necessarily protect the entirety of the ecosystem. Marine protected areas (MPAs) offer a unique solution that encompasses not only target species for harvesting, but also the interactions surrounding them and the local environment as a whole. Direct benefits of MPAs to fisheries (for example, spillover effects) have been well documented around the world. Indirect benefits have also been shown for several cases among species such as abalone and fishes in Central California. Most importantly, MPAs can be effective at protecting existing kelp forest ecosystems and may also allow for the regeneration of those that have been affected.
Pterygophora californica is a large species of kelp, commonly known as stalked kelp. It is the only species in its genus Pterygophora (Ruprecht, 1852). It grows in shallow water on the Pacific coast of North America where it forms part of a biodiverse community in a "kelp forest".
Some species, called a "keystone species" form a central supporting hub unique to their ecosystem. The loss of such a species results in a collapse in ecosystem function, as well as the loss of coexisting species. Keystone species are usually predators due to their ability to control the population of prey in their ecosystem. The importance of a keystone species was shown by the extinction of the Steller's sea cow ("Hydrodamalis gigas") through its interaction with sea otters, sea urchins, and kelp. Kelp beds grow and form nurseries in shallow waters to shelter creatures that support the food chain. Sea urchins feed on kelp, while sea otters feed on sea urchins. With the rapid decline of sea otters due to overhunting, sea urchin populations grazed unrestricted on the kelp beds and the ecosystem collapsed. Left unchecked, the urchins destroyed the shallow water kelp communities that supported the Steller's sea cow's diet and hastened their demise. The sea otter was thought to be a keystone species because the coexistence of many ecological associates in the kelp beds relied upon otters for their survival. However this was later questioned by Turvey and Risley, who showed that hunting alone would have driven the Steller's sea cow extinct.
Bull kelp, Nereocystis luetkeana, a northwestern American species. Used by coastal indigenous peoples to create fishing nets. Giant kelp, Macrocystis pyrifera, the largest seaweed. Found in the Pacific coast of North America and South America. Kombu, Saccharina japonica (formerly Laminaria japonica) and others, several edible species of kelp found in Japan.
The rocky reef, kelp forest and emergent rock habitats in these MPAs support numerous species of invertebrates, plants, fish and marine mammals; among them are garibaldi, rockfish, octopus, gorgonians, nudibranchs, bat rays, kelp bass and many more. The sedentary, invertebrate species located there are set aside from recreational harvest.
Multiple kelp species often co-exist within a forest; the term understory canopy refers to the stipitate and prostrate kelps. For example, a "Macrocystis" canopy may extend many meters above the seafloor towards the ocean surface, while an understory of the kelps "Eisenia" and "Pterygophora" reaches upward only a few meters. Beneath these kelps, a benthic assemblage of foliose red algae may occur. The dense vertical infrastructure with overlying canopy forms a system of microenvironments similar to those observed in a terrestrial forest, with a sunny canopy region, a partially shaded middle, and darkened seafloor. Each guild has associated organisms, which vary in their levels of dependence on the habitat, and the assemblage of these organisms can vary with kelp morphologies. For example, in California, "Macrocystis pyrifera" forests, the nudibranch "Melibe leonina", and skeleton shrimp "Caprella californica" are closely associated with surface canopies; the kelp perch "Brachyistius frenatus", rockfish "Sebastes" spp., and many other fishes are found within the stipitate understory; brittle stars and turban snails "Tegula" spp. are closely associated with the kelp holdfast, while various herbivores, such as sea urchins and abalone, live under the prostrate canopy; many seastars, hydroids, and benthic fishes live among the benthic assemblages; solitary corals, various gastropods, and echinoderms live over the encrusting coralline algae. In addition, pelagic fishes and marine mammals are loosely associated with kelp forests, usually interacting near the edges as they visit to feed on resident organisms.
Kelp beds provide a nursery area for many marine species and a biodiverse habitat. The grazing behaviour of sea urchins, particularly the green sea urchin, "Strongylocentrotus droebachiensis", restricts the development of new growth of "L. hyperborea". If the urchins become too numerous, whole areas normally dominated by kelp may become "urchin barrens", denuded of kelp and supporting a much less biodiverse community based on encrusting coralline algae.
Where the bottom is rocky and affords places for it to anchor, giant kelp forms extensive kelp beds with large "floating canopies". When present in large numbers, giant kelp forms kelp forests that are home to many marine species that depend upon the kelp directly for food and shelter, or indirectly as a hunting ground for prey. Both the large size of the kelp and the large number of individuals significantly alter the availability of light, the flow of ocean currents, and the chemistry of the ocean water in the area where they grow.
Gas-filled floats called "pneumatocysts" provide buoyancy in many kelps and members of the Fucales. These bladder-like structures occur in or near the "lamina", so that it is held nearer the water surface and thus receives more light for photosynthesis. Pneumatocysts are most often spherical or ellipsoidal, but can vary in shape among different species. Species such as "Nereocystis luetkeana" and "Pelagophycus porra" bear a single large pneumatocyst between the top of the stipe and the base of the blades. In contrast, the giant kelp "Macrocystis pyrifera" bears many blades along its stipe, with a pneumatocyst at the base of each blade where it attaches to the main stipe. Species of "Sargassum" also bear many blades and pneumatocysts, but both kinds of structures are attached separately to the stipe by short stalks. In species of "Fucus", the pneumatocysts develop within the lamina itself, either as discrete spherical bladders or as elongated gas-filled regions that take the outline of the lamina in which they develop.
Though urchins are usually the dominant herbivores, others with significant interaction strengths include seastars, isopods, kelp crabs, and herbivorous fishes. In many cases, these organisms feed on kelp that has been dislodged from substrate and drifts near the ocean floor rather than expend energy searching for intact thalli on which to feed. When sufficient drift kelp is available, herbivorous grazers do not exert pressure on attached plants; when drift subsidies are unavailable, grazers directly impact the physical structure of the ecosystem. Many studies in Southern California have demonstrated that the availability of drift kelp specifically influences the foraging behavior of sea urchins. Drift kelp and kelp-derived particulate matter have also been important in subsidizing adjacent habitats, such as sandy beaches and the rocky intertidal.
Monterey Bay is home to many species of marine mammals, including sea otters, harbor seals, and bottlenose dolphins; as well as being on the migratory path of Gray and Humpback Whales and a breeding site for elephant seals. Killer whales are also found along the coast, especially when Gray whales migrate, as they hunt the whales during their migration north. Many species of fish, sharks, mollusks such as abalone and squid, birds, and sea turtles also live in the bay. Several varieties of kelp grow in the bay, some becoming as tall as trees, forming what is known as a kelp forest.
Common fish found in the epipelagic zone include:
Common fish found in the neritic zone include:
Common fish found in the rocky intertidal zone include:
Many different species of fish rely on the kelp forests as a source of life. Populations of fish are larger in areas with a higher concentration of kelp. Fish that live in and rely on kelp forests include kelp surfperch ("Brachyistius frenatus"), kelp bass ("Paralabrax clathratus"), giant kelpfish ("Heterostichus rostratus"), and kelp rockfish ("Sebastes atrovirens"). A study conducted near San Luis Obispo, California showed that when kelp was removed from a nearby reef, fish biomass declined by 63%. Juvenile fish rely on kelp beds a nursery grounds. Southern California Edison built a off San Clemente in 2008.
Classic studies in kelp forest ecology have largely focused on trophic interactions (the relationships between organisms and their food webs), particularly the understanding and top-down trophic processes. Bottom-up processes are generally driven by the abiotic conditions required for primary producers to grow, such as availability of light and nutrients, and the subsequent transfer of energy to consumers at higher trophic levels. For example, the occurrence of kelp is frequently correlated with oceanographic upwelling zones, which provide unusually high concentrations of nutrients to the local environment. This allows kelp to grow and subsequently support herbivores, which in turn support consumers at higher trophic levels. By contrast, in top-down processes, predators limit the biomass of species at lower trophic levels through consumption. In the absence of predation, these lower-level species flourish because resources that support their energetic requirements are not limiting. In a well-studied example from Alaskan kelp forests, sea otters ("Enhydra lutris") control populations of herbivorous sea urchins through predation. When sea otters are removed from the ecosystem (for example, by human exploitation), urchin populations are released from predatory control and grow dramatically. This leads to increased herbivore pressure on local kelp stands. Deterioration of the kelp itself results in the loss of physical ecosystem structure and subsequently, the loss of other species associated with this habitat. In Alaskan kelp forest ecosystems, sea otters are the keystone species that mediates this trophic cascade. In Southern California, kelp forests persist without sea otters and the control of herbivorous urchins is instead mediated by a suite of predators including lobsters and large fishes, such as the California sheephead. The effect of removing one predatory species in this system differs from Alaska because redundancy exists in the trophic levels and other predatory species can continue to regulate urchins. However, the removal of multiple predators can effectively release urchins from predator pressure and allow the system to follow trajectories towards kelp forest degradation. Similar examples exist in Nova Scotia, South Africa, Australia and Chile. The relative importance of top-down versus bottom-up control in kelp forest ecosystems and the strengths of trophic interactions continue to be the subject of considerable scientific investigation.
Species in the genus "Durvillaea" are also sometimes called 'bull kelp', but this is just a shortening of the common name southern bull kelp. "Durvillaea" is a genus in the order Fucales and, though superficially similar in appearance, is not a true kelp (all of which are in the order Laminariales)
The fly oviposits in dead kelp that washes up on beaches. This is the only place it lays eggs, and it can do so on many species of kelp and seaweed, including species of "Laminaria" and "Fucus". A female fly lays up to five clutches of 80 eggs each. The larvae feed upon the bacteria coating the dead kelp. The life cycle is about 11 or 12 days long.