Saltwater fish , also called marine fish or sea fish , are fish that live in seawater . Saltwater fish can swim and live alone or in a large group called a school .
61-714: Cynoscion macdonaldi Gilbert, 1890 The Totoaba , Totuava , or the Giant of the Gulf ( Totoaba macdonaldi ) is a species of marine fish and the largest member of the drum family Sciaenidae that is endemic to the Gulf of California in Mexico . It is the only species in the genus Totoaba . Originally the Totoaba was an abundant species, now it is considered endangered due to human related threats that contributed to its population decline. Although
122-571: A fossil otolith assigned to the extinct species T. fitchi is known from the Oclese Sand Formation in Kern County , California, suggesting that it reached as far north as there during the late part of the Early Miocene . New studies have indicated a possible expansion in range for the living Totoaba population from their historical southern limit of west Bahía Concepción and east in
183-632: A bust, which nearly drove pacific sardines to local extirpation. As climate change accelerates, the coastal upwelling that pelagic species in East Pacific waters rely on may weaken due to increasingly invariable winds, which can be detrimental to the spawning and rearing of forage fish. Californian anchovies are going to be heavily affected as their population biomass usually booms during cooler water years with high coastal productivity. Their boom & bust cycles will be stronger and occur more frequently than previously observed, which has already resulted in
244-465: A habitat which are physical materials like rocks, reefs, and sand or the vegetation like the amount of algae, water plants, and saltmarsh . Specific fish live in specific habitats based on what they eat or what cycle of life they are currently at, another thing is the amount of salt that is in the water at that specific location. Some ocean habitats are not technically in the ocean and these are called estuaries , areas when oceans and rivers meet creating
305-486: A large fraction of the marine biomass in waters off the west coast of North America , where they are a vital keystone species in coastal pelagic waters. However, they are subject to seasonal boom & bust cycles that are chiefly caused by changes in water temperature and food availability; regularly switching places as the forage fish of prominence with the sardine during years defined by colder water temperatures, which makes them vulnerable to climate change . They have
366-495: A low level, perhaps a bit larger than when the commercial fishery was banned in 1975. Totoabas are still caught as bycatch in fishing for other finned fish and for shrimp, and in illegal fishing for Totoaba directly. Some Totoabas are illegally exported to the United States, often misidentified as white seabass . The government of Baja California has authorized commercial raising of Totoaba in fish farms . Although now done at
427-444: A major cause of the depletion of the Totoaba population. Changes in salinity cause the response of physiological processes to change which can impact the survival of a population by affecting growth and reproduction. With the loss of the freshwater flow from the river, salinity in the delta is usually 35 ppt or higher, it ranges from >1 psu at the head of the river to 20 psu in the delta. While this alteration has been considered one of
488-419: A marine life habitat . Some of them are the temperature of the water, the quality, and quantity of water (flow and depth). Other components that can also contribute to the habitat of saltwater fish are pH level, salt level, and alkalinity level. Levels of nitrates and phosphates are also relevant, particularly when considering conditions for fish in captivity. There are other physical features that contribute to
549-457: A mixture of salt water and freshwater making a different habitat for different types of fish and creatures to live in. The ocean is home to organisms as large as whales and as small as microscopic marine organisms such as phytoplankton . However, the vast majority of ocean life that humans are exposed to is simple saltwater fish. Saltwater fish can live in the deepest depths of the ocean where no sunlight can penetrate, but they can also live on
610-547: A multi-million dollar industry in the United States . About 10 million marine fish are imported into the United States each year for aquarium use. The United States imports more saltwater fish than any other country in the world. There are approximately 2,000 different species of saltwater fish that are imported and used in captivity . In many circumstances, fish used for marine trade are collected using harmful tactics such as cyanide . One way that people are trying to protect
671-479: A peak in March and April. The Totoaba are an iteroparous species with asynchronous ovarian dynamics suggesting they are batch spawners. One-year-old Totoabas are metabolically most efficient in brackish water of about 20 parts per thousand (ppt) salinity , a level that occurred naturally in the delta before the diversion of water from the river that occurred in the middle of the 20th century. The diversion of water from
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#1732868618529732-591: A relatively large scale by private fish farms, much of the initial research in the captive keeping, breeding and raising of totoaba was done at the Autonomous University of Baja California . Formerly abundant and subject to an intensive fishery , the Totoaba has become rare, and was listed by the Convention on International Trade in Endangered Species of Wild Fauna and Flora under Appendix I in 1976. It
793-574: A safer bet for eating in large portions similar to salmon . The Californian anchovy is currently not a listed species even though its biomass has seen a decline during the 21st century. This is due to the natural oscillations in population size between anchovies and pacific sardines that are determined by water temperature, prey availability and rate of upwelling . The processes that drive these oscillations, or boom & bust cycles, are still largely unknown. Population stressors like overfishing or unusual oceanic conditions can have an outsized effect on
854-674: A separate "bay" form of the Californian anchovy that has fewer vertebrae than the oceanic "green-back" form, a proportionally larger head, a tan to transparent dorsum due to the near absence of guanine crystals in their chromatophores , and a residential lifestyle with no migration to coastal waters. Hubbs was confident enough about its existence that he described it as a subspecies named Engraulis mordax nanus Girard . However, all anchovies undergo regular shifts in dorsum color due to salinity changes during their migrations and transitions between their life stages, and that anchovies that closely resemble
915-552: A small but dedicated community of gastronomic fans wherever they are sold fresh. They are taken by anglers for use as bait or for personal consumption. California anchovies in the Monterey Bay have been observed with heightened levels of microplastics, mistaking them for floating particulates of food. However, their low trophic level means that their rate of bioaccumulation is relatively low compared to higher trophic level fish like lingcod or striped bass , which makes them
976-615: A small commercial fishery; mainly used as bait for fishermen or fish meal, with a dedicated small following as a food fish in San Francisco . Californian anchovies exhibit the basic anchovy body form like a large sub-terminal mouth that extends past the eye, a centrally located single dorsal fin on a compressed & elongated body, a forked caudal fin , the absence of a visible lateral line , and weak, shiny scales colored by crystalline guanine that complete its countershaded camouflage. The only way to confidently tell them apart from
1037-404: A source of food, the global seafood market is a major threat to the biodiversity of fishes. Bycatch is a direct effect of overfishing and is defined as the unwanted capture of different marine organisms during industrial fishing. This results in many different species of fish dying after they are captured and discarded. Data on bycatch is often unclear and not well recorded but it is estimated that
1098-403: A way to identify Totoaba swim bladders on-site of legal and illegal trades, that is efficient, convenient, inexpensive, and gives reliable results called real-time fluorescence-based recombinase-aid amplification (RF-RAA). Helping authorities be equipped to handle the increase in illegal imports and the market regulations surrounding Totoaba swim bladders. Commercial fishing for Totoaba began in
1159-497: A wild salmon would due to differences in artificial and natural selection. Artificial selection that chooses phenotypic traits that are desired for human consumption will alter the genetics of wild stocks if farmed fish interact and breed with wild populations. This would result in the reduction of fitness related traits that wild stocks possess which is a serious threat to these populations. Northern anchovy The Californian anchovy or northern anchovy ( Engraulis mordax )
1220-637: Is a species of anchovy found in the Eastern Pacific Ocean , ranging from Mexico to British Columbia . It is a small, Clupeoid fish with a large mouth and a long, laterally compressed body, which strongly resembles the European Anchovy ( Engraulis encrasicolus) with only slight differences in girth and fin position. They have a euryhaline lifestyle defined by regular migrations between bays and open ocean for both spawning and foraging. Like Pacific sardines ( Sardinops sagax) , they compose
1281-437: Is a spinous portion, and the posterior dorsal is a soft-rayed portion providing balance, maneuverability, and protection. Its pectoral fins are located towards the head of the fish right behind the operculum and are exceedingly long with the pelvic fins located right beneath it. Its anal fin is located before the peduncle and it's caudal fin most closely resembles a truncate shaped tail. The Totoabas' weight and size makes it
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#17328686185291342-604: Is also listed by the International Union for Conservation of Nature as vulnerable, by NatureServe as critically imperiled and under the U.S. Endangered Species Act as endangered in 1979. Making it illegal to catch Totoaba since 1975 when it was placed on the Mexican Endangered Species List. On 16 April 2015, Enrique Peña Nieto , the President of Mexico , announced a program of rescue and conservation of
1403-414: Is defined as the farming of aquatic organisms in controlled environments for the purpose of providing food and resources for humans. Aquaculture can take place in both marine and freshwater environments, however, because this is the saltwater fish page this entry will only cover the effects of aquaculture on marine fishes. The rising global demand for fish has contributed to the increase in aquaculture. Due to
1464-475: Is defined as the mass removal of fish from a body of water that results in halting the ability for breeding populations to replenish what has been removed. Fish is one of the most popular foods in the world and consumption has continued to rise with the growing human population and will continue to do so. The value of the global seafood market has seen a 15% increase from 2016 to 2020 and is projected to increase even more by 2023. Although it provides many people with
1525-730: Is divided into 3 phenotypically distinct sub-populations: a northern subpopulation between British Columbia and Monterey Bay , a central subpopulation between San Francisco Bay and coastal waters near El Rosario in central Baja California , and a southern subpopulation from Cedros Island southwards into the mouth of the Gulf of California . Although these subpopulations somewhat differ in certain characteristics like operculum width, body size, transferrin pattern types, and spawning times, they are not genetically distinct enough to warrant reclassification into separate subspecies. Most California anchovies begin their lives hatching in coastal waters or in estuaries in late spring, though spawning
1586-504: Is erroneously believed by many Chinese to be a treatment for fertility, circulatory, and skin problems. The swim bladders are often smuggled to Hong Kong where they are illegal, but import screenings are lax, and from there they are sometimes forwarded to the Chinese mainland where import screenings are stricter. This trade once focused on the Chinese bahaba , but as its population became depleted,
1647-558: Is harmful because it pollutes the surrounding ecosystem and can cause problems like eutrophication, transmission of parasites and diseases to wild populations and developmental abnormalities on surrounding wild fish. Genetic pollution of wild fish populations is a common risk that cage aquaculture faces. For example, there are many scientific papers that have examined the effects of Atlantic Salmon escaping from their enclosures and interacting with wild populations. Farmed salmon have lower fitness (low survival rates and reproductive success) than
1708-417: Is known to happen year-round. The larvae live in the photic zone of the waters near their birth as ichthyoplankton , where they float around at the mercy of tidal and oceanic currents and are thus regularly consumed by planktivores like pacific herring and other anchovies until the survivors mature into schooling sub-adults and begin moving into more saline waters, which physiologically corresponds with
1769-476: Is not impacted but that reproductive activity by adults is not as negatively affected due to environmental changes caused from damming. Each life stage of the Totoaba osmoregulate differently. Totoaba eggs are osmoconformers. Their larvae are stenohaline able to osmoregulate in salinity levels of 20 to 34 psu, this life stage is the less tolerant to extreme salinity. Juveniles on the other hand can survive in salinity ranging from 5 to 40 psu. The change in salinity in
1830-442: Is silvery with darker fins and a light belly. There is no sexual dimorphism between the males or females. The juveniles tend to be spotted in comparison to the adults, specifically having a spotted second dorsal fin. The Totoaba have an elongated compressed fusiform body shape with a terminal oblique mouth and lower jaw that projects slightly. The Totoaba has two dorsal fins with a clear separation between them. The anterior dorsal fin
1891-617: The Euphausiidae family were also identified. This more id depth understanding of diet allows for a better understanding of dietary needs for aquaculture feed considerations, biodiversity, trophic relationships, and ecology. It is important to note that discovering the diet of the Totoaba has proven difficult because their diet varies depending on the life stage its' in. However, in juveniles examined in 1972, they found amphipods , crustaceans , and juvenile fishes ( Micropogon sp., Mugil cephalus, and Leuresthes sardina ) so although limited by size
Totoaba - Misplaced Pages Continue
1952-892: The Salish Sea or San Francisco Bay . They typically have a lifespan between 4 and 7 years, with reproduction occurring yearly after maturing throughout their lives. As sardine populations declined in the Pacific during the 1940s and 50's, fish packers in America started canning the more abundant local anchovies . Total hauls increased over this time from 960 tons in 1946 to 9,464 tons in 1947 and peaking at almost 43,000 tons in 1953. From 1949 to 1955, they were restricted for all uses but bait fish in California . In 2010, reported American hauls totaled 2,100 metric tons. Most Californian anchovies today are fished for use in animal feed and as bait fish , with
2013-430: The coral reefs is by breeding marine fish in captivity . Captive-bred fish are known to be healthier and likely to live longer. Captive-bred fish are less susceptible to disease because they have not been exposed to the wild and they have not been damaged during the shipment process. Fish that are bred in captivity are already accustomed to aquarium habitats and food. There are many different components that make up
2074-401: The oceanic whitetip shark is considered critically endangered because of its value in the seafood market. Their rapidly declining population is due to people overfishing them for their fins. They are a popular species of shark used in shark fin soup because of the size of their fins. All sharks are used for shark fin soup, however, certain species of sharks are preferred over others because of
2135-472: The "bay" form have been collected off the coast of Northern California . More research, preferably genetic analyses, on the "bay" form present in San Francisco Bay is needed to support its existence as a separate subspecies. The native range of the Californian anchovy is demarcated roughly between the nearshore waters off Haida Gwaii to the north and the Gulf of California to the south. Their range
2196-422: The 1920s. The catch reached 2,000 t (2,200 short tons) in 1943, but had fallen to only 50 t (55 short tons) in 1975, when Mexico protected the Totoaba and banned the fishery. Anecdotal evidence suggests that Totoabas were very abundant prior to the start of the commercial fishery, but no hard evidence now indicates natural population size. Recent studies indicate that the Totoaba population has stabilized at
2257-563: The Colorado River within the United States leaves little or no fresh water to reach the delta, greatly altering the environment in the delta, and the salinity of the upper Sea of Cortez . The flow of fresh water to the mouth of the Colorado since the completion of the Hoover and Glen Canyon dams has been only about 4% of the average flow during the period from 1910 to 1920. This is considered to be
2318-516: The European anchovy besides their range is to measure where the posterior side of their dorsal fins terminate on their body, which vertically matches exactly where the anal fin begins for Californian anchovies. Trawling surveys in San Francisco Bay starting from the 1920s by famous ichthyologist Carl Leavitt Hubbs up to the present by scientists from UC Davis seem to support the existence of
2379-426: The Totoaba population has declined due to nearly 50 years of overfishing, they have maintained their historical distribution range across the Gulf of California, inhabiting the northern part of the Gulf, the south of La Paz, the west of Baja California Sur, and the east of Mármol,Sinaloa. Interestingly, the genus Totoaba appears to have had a slightly wider range on the western North American coast in prehistoric times;
2440-447: The U.S. alone discards 17–22% of their catch annually. The Mesopredator release hypothesis is one of the indirect effects of overfishing that is also often referred to as " fishing down the food web ". This phenomenon means as fisheries deplete large apex predatory species, mid-sized predatory species increase in abundance and assume the role as top predators on the food web. This impacts the food web in marine environments and disrupts
2501-519: The balance of the ecosystem and is likely to cause trophic cascades. Profitable fish stocks like the bluefin tuna are decreasing in numbers because of high demand. According to the IUCN Red List, the Pacific bluefin tuna , Atlantic bluefin tuna , and southern bluefin tuna are classified as vulnerable, endangered and critically endangered all due to over-exploitation. According to the IUCN Red List,
Totoaba - Misplaced Pages Continue
2562-463: The bottom of coastal areas where the habitat floor is soft with sand. While there is no formal compilation of the color, shape, or other characteristics besides size and weight of the Totoaba, a website dedicated to the photography and species information of Mexican fishes has compile a cohesive enough species description of the Totoaba. The Totoaba can reach a size of up to 2 meters (6.5 feet) and weight 135 kilograms (297 pounds). The Totoaba coloration
2623-408: The damming of the Colorado River specifically the upper Gulf which is their spawning and nursery area. The Totoaba habitats consists of either brackish or marine waters depending on their life stage. They mainly inhabit coastal areas, but have been found in rocky reef areas. Their water depth ranges from 1 to 70 meters, and temperature ranges from 15-29 Celsius. As a demersal fish they spend time at
2684-436: The decline of many wild fish stocks, aquaculture is the fastest growing food production system that contributes about 50% of the worlds fish supply. There is a lot of debate on whether or not aquaculture is an environmentally sustainable practice, yet the socioeconomic benefits that humans receive is tough to argue against. That being said there are significant negative effects that aquaculture, especially cage aquaculture, has on
2745-476: The diet if the juveniles is comparable to the diet of the adults. The Totoaba are long-lived individuals that may live up to 20-25 years, but sexual maturity is usually not reached until females are seven years old and males are six years old. Female and male Totoaba measured length during their first sexual maturity is between 1.3 and 1.2 meters. The Totoaba's population growth is slow, with a minimum population doubling time of 4.5 to 15 years. The Totoaba spawn in
2806-410: The habitat of juveniles has not affected their distribution or abundance. Another threat to the Totoaba is from human poaching : the swim bladder , commonly referred to as "maw" is a valuable commodity, as it is considered a delicacy in Chinese cuisine; the meat is also sought-after for making soups. It can fetch high prices – 200 bladders may be sold for $ 3.6 million at 2013 prices – as it
2867-471: The increased guanine crystals (and therefore bluer & greener dorsum coloration) in their chromatophores ; eventually making it into the open ocean where they become adults. Adult schools of anchovies regularly move between deeper and shallow waters to feed on plankton during their diel vertical migration until temperature and prey abundance cues certain cohorts of the population to either begin spawning in shallow inshore waters or inside large estuaries like
2928-415: The large size of their fins. The great white shark is listed as vulnerable on the IUCN Red List because its fins are commonly used in shark fin soup and has led to people over harvesting them for their fins. This shark belongs to the class Chondrichthyes that includes all sharks, skates and rays. The great white shark is one of the many examples of shark species threatened by human consumption because of
2989-794: The largest species in the drum family, together with the similar-sized Chinese bahaba ( Bahaba taipingensis ) and meagre ( Argyrosomus regius ). The Totoabas' diet consists of finned fish and crustaceans . A recent study done in 2023 has used metabarcoding for the first time to identify a more specific diet for wild Totoaba. The study found 11 species of prey consumed by the Totoaba: Pacific anchovy ( Centengraulis mysticetus ), Flathead grey mullet ( Mugil cephalus ), Bigeye croaker ( Micropogonias megalops ), Northern anchovy ( Engraulis mordox ), Ocean whitefish ( Caulolatilus princeps ), Milkfish ( Chanos chanos ), and Pacific sardine ( Sardinpos sagax ). The specific crustacean known as krill from
3050-527: The mouth of the Colorado River Delta , serving as a nursery of shallow, brackish waters for the young fish. The Totoaba population is found in two distinct groups. Larval and juvenile stages occupying the Colorado delta, while the adult breeding population lives for most of the year in deeper water towards the middle of the Gulf of California. The breeding timeframe starts in January and continues til May with
3111-650: The mouth of the El Fuerte River, Sinaloa to more southward bound areas such as in the Bay of La Paz and off Mármol. However, this range expansion is still being researched as a lack of information on the Totoaba prior to its' decline is largely unknown. The Totoaba use different habitat areas of the Gulf for their ontogenetic migratory pattern which consist of pre-recruits, juveniles, pre-adults, and adults. Each location provides different environments to sustain that specific life stage. However, their habitat has been altered due to
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#17328686185293172-452: The ocean eat things such as algae and flowering seagrasses . Many herbivores' diets consist of primarily algae. Most saltwater fish will eat both macroalgae and microalgae . Many fish eat red, green, brown, and blue algae, but some fish prefer other types. Most saltwater fish that are carnivores will never eat algae under any circumstances. Carnivores' diets consist of shrimp , plankton , or tiny crustaceans . Saltwater aquariums are
3233-415: The possibility of introducing an invasive species if the fish being reared are non-native . Fish sewage is the combination of fish feed, fecal material and antibiotics that is accumulated on the seafloor and in the water column from fish that are being farmed. It is not only harmful to wild fish stocks but it also poses a threat to marine plant life which is often a food source for wild fish stocks. Fish sewage
3294-588: The reasons for Totoaba population decline since historically the Totoaba have been considered an estuarine-dependent species that use the Upper Gulf of California for spawning, new studies done in 2023 have indicated that the Totoaba continue to use the modified breeding grounds. This suggest that either the Totoaba are resilient and adaptable to changes occurring in their natural habitat or migrating to brackish waters served other purposes outside meeting breeding conditions. Regardless this does not mean reproduction success
3355-530: The shark fin soup, large population declines of this class has been noted since the early 2000s due to the high demand for their fins, gill rakers and liver oil. The Atlantic cod was historically abundant in the waters off the coast of New England . Due to its low fat content and dense white flesh, this fish is a popular choice among humans. Now considered vulnerable, its populations have both decreased in abundance and their distribution has shifted from northern to southern areas due to overfishing. Aquaculture
3416-465: The surface of the water. Marine fish face many anthropogenic threats. Common human-induced threats include overfishing, pollution, habitat loss and destruction, climate change and invasive species. The aforementioned threats all come with a multitude of negative direct and indirect affects to marine ecosystems. With the human population growing at an exponential rate, these threats are likely to continue to be prevalent in marine ecosystems. Overfishing
3477-578: The surrounding environment. Cage aquaculture involves rearing aquatic organisms in natural water sources while enclosed in a mesh/net cage that allows water from the surrounding environment to freely flow in and out. Cage aquaculture in marine environments has been particularly controversial because of the effects it has on the surrounding ecosystem thus, affecting wild marine fish populations. The main impacts of cage aquaculture are reduced water quality from fish sewage, high potential of genetic pollution of wild stocks due to escapees from aquaculture cages and
3538-421: The swim bladders. More recently, both Mexican and Chinese authorities have tightened checks and performed raids, resulting in large confiscations and several arrests. The Totoaba is suitable for fish farming due to the relative ease of breeding it in captivity and its high growth rate. Although this mainly is done to supply the food market, tens of thousands of Totoaba hatched in captivity have been released into
3599-454: The trade shifted to the related Totoaba. The illegal Totoaba fishery also threatens the vaquita , a critically endangered porpoise endemic to the northern Gulf of California that appears to be doomed to extinction unless the setting of gillnets in its habitat can be halted. The Totoaba swim bladder is often used for identification more than a morphological description of the fish due to the illegal trade of it. Recent research in 2024 has created
3660-535: The vaquita and the Totoaba, including closures and financial support to fishermen in the area. This closure is necessary as they were still caught as a bycatch in the legal fishery for other species. Some commentators believe the measures fall short of what is needed to save the vaquita. The Chinese trade in Totoaba swim bladders has been a primary reason for its decline. Despite being illegal, this trade often happened quite openly and traders reported being warned before checks by Chinese authorities, allowing them to hide
3721-466: The wild in an attempt to save the species. Marine fish Saltwater fish are very commonly kept in aquariums for entertainment . Many saltwater fish are also caught to be eaten, or grown in aquaculture . However, many fish species have been overfished and are otherwise threatened by marine pollution or ecological changes caused by climate change . Fishes that live in the ocean can be carnivores , herbivores , or omnivores . Herbivores in
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