The ocean covers over 70% of the Earth’s surface and contains a vast diversity of fish species. While estimates vary, there are likely over 20,000 different species of fish living in the world’s oceans. However, only a small percentage of these species are abundant and widespread. So which fish are the most common in the ocean? The answer depends on the geographic location, depth, and marine environment. Overall, small schooling forage fish like herrings, anchovies, and sardines are some of the most numerous fish globally. Larger predatory fish like tunas, sharks, and billfishes are also found worldwide but in lower numbers. Regionally, fish like cod, pollock, hake, and salmon dominate cooler northern waters while tropical and subtropical oceans host large populations of jacks, snappers, groupers, and mackerels. Here is an overview of some of the most common saltwater fish found across the world’s oceans.
Herrings
Herrings are small silvery schooling fish belonging to the family Clupeidae. They inhabit temperate and polar oceans worldwide, occurring in massive numbers in certain regions. The most abundant herring species include the Atlantic herring (Clupea harengus) in the North Atlantic and Pacific herring (Clupea pallasii) in the North Pacific. These cold-water herrings can grow over a foot long and form schools containing hundreds of thousands or even millions of individuals. Herrings are a key forage fish, feeding on plankton and serving as an important food source for larger predatory fish, seabirds, and marine mammals. Their abundance and high energy content make herrings a hugely important fish from ecological and commercial perspectives. Herrings have been fished extensively for human consumption, fish meal, and oil.
Anchovies
Anchovies are another vital small schooling fish that rank among the most plentiful fish globally. They belong to the family Engraulidae and occur in schools numbering in the tens or hundreds of thousands. Anchovies thrive in pelagic waters of tropical and temperate oceans throughout the world. The northern anchovy (Engraulis mordax) supports a massive fishery off the west coast of North America while the Peruvian anchovy (Engraulis ringens) is crucial to the waters off South America. These small (6-9 inches long) silvery fish feed on plankton and provide essential nutrition to an array of larger predatory fish, marine mammals, and seabirds that depend on their abundance. Anchovies are heavily fished for products like fishmeal but have seen large population fluctuations over time, with El Nino events causing periodic crashes.
Sardines
Closely related to herrings and anchovies are the sardines, small schooling oily fish in the family Clupeidae. Sardines inhabit tropical and temperate coastal waters around the world, congregating in huge schools that can be seen swarming near the ocean’s surface.Well-known species include the European pilchard (Sardina pilchardus) of the eastern Atlantic and Mediterranean and the Indian oil sardine (Sardinella longiceps) of the Indo-Pacific oceans. Other prolific members of the more than 20 recognized sardine species include blueback herring (Alosa aestivalis), Pacific sardine (Sardinops sagax) and Australian sardine (Sardinops sagax). Sardines feed on plankton and play a vital ecological role converting microscopic algae and animals into biomass that supports higher trophic levels. Sardines are heavily fished for human food but have experienced large natural population fluctuations similar to anchovies.
Menhadens
Menhadens are oily filter-feeding fish in the herring family Clupeidae that occur in great numbers off the Atlantic and Gulf coasts of North America. The Gulf menhaden (Brevoortia patronus) and Atlantic menhaden (Brevoortia tyrannus) both migrate in large schools along the coasts and estuaries of North America. These schooling fish help regulate plankton and play an integral role converting plankton into protein and oil that supports a wide variety of larger fish, seabirds, and marine mammals. Menhadens are one of the most abundantly caught fish in the United States, reduced to fish meal, fish oil, and fertilizer. Their populations have been monitored and managed closely to prevent overfishing.
Mackerels
Mackerels are fast-swimming predatory fish that belong to the family Scombridae and inhabit temperate and tropical oceans worldwide. Common species of mackerels include the chub mackerel (Scomber japonicus), Atlantic mackerel (Scomber scombrus), king mackerel (Scomberomorus cavalla), and Spanish mackerel (Scomberomorus maculatus). These active schooling fish feed on small crustaceans, mollusks, and small fish. Mackerels are prized sporting and table fish. Several species support extensive commercial fisheries for human food due to their rich flavor and abundance, though their populations fluctuate. King mackerel and Spanish mackerel are common along the coasts of North America and support sustainable regional fisheries.
Jacks
Jacks comprise a group of active, predatory fish belonging to the family Carangidae. They inhabit tropical and subtropical waters worldwide, occurring in large numbers offshore as well as around reefs and islands. Some of the most common and abundant jacks include species like blue runner (Caranx crysos), crevalle jack (Caranx hippos), yellow jack (Caranx bartholomaei), and horse-eye jack (Caranx latus). Jacks prey on other small schooling fish and crustaceans and often congregate in large vigorous packs numbering in the tens of thousands. Schools of jacks represent considerable biomass and provide food for larger pelagic predators. Several jack species support commercial and recreational fisheries, though their populations are considered quite robust overall.
Herrings
– Atlantic herring (Clupea harengus): found in North Atlantic and North Pacific
– Pacific herring (Clupea pallasii): found in North Pacific
– Araucanian herring (Clupea bentincki): found off Chile and Peru
– Australian herring (Arripis georgianus): found off southern Australia
Anchovies
– Northern anchovy (Engraulis mordax): found off North America
– Southern African anchovy (Engraulis capensis): found off southern Africa
– European anchovy (Engraulis encrasicolus): found in the Mediterranean and Black Sea
– Peruvian anchovy (Engraulis ringens): found off Peru and Chile
– Japanese anchovy (Engraulis japonicus): found in the northwest Pacific
Sardines
– European pilchard (Sardina pilchardus): found in eastern Atlantic and Mediterranean
– Pacific sardine (Sardinops sagax): found in northeast Pacific
– South American pilchard (Sardinops sagax): found off southwest South America
– Madeiran sardinella (Sardinella maderensis): found near Madeira islands
– Indian oil sardine (Sardinella longiceps): found in the Indo-Pacific
Menhadens
– Gulf menhaden (Brevoortia patronus): found in the Gulf of Mexico
– Atlantic menhaden (Brevoortia tyrannus): found off Atlantic coast of North America
– Yellowfin menhaden (Brevoortia smithi): found off the Brazilian coast
– Chinese menhaden (Nibea coibor): found in the Indo-West Pacific
Mackerels
– Chub mackerel (Scomber japonicus): found worldwide in temperate and tropical seas
– Atlantic mackerel (Scomber scombrus): found in the north Atlantic Ocean
– King mackerel (Scomberomorus cavalla): found off North America and Gulf of Mexico
– Cero mackerel (Scomberomorus regalis): found in the western Atlantic Ocean
– Spanish mackerel (Scomberomorus maculatus): found in warm waters worldwide
Jacks
– Blue runner (Caranx crysos): found worldwide in tropical and subtropical waters
– Crevalle jack (Caranx hippos): found in tropical and subtropical waters near islands and coastlines
– Yellow jack (Caranx bartholomaei): found in the western Atlantic Ocean
– Horse-eye jack (Caranx latus): found in the eastern Pacific Ocean near shore and around islands
– Black jack (Caranx lugubris): found in the Indo-Pacific region
Abundance and Importance
Small schooling fish like herring, anchovy, and sardines typically rank among the most abundant fish in the oceans. Their huge biomass and energetic value supports entire food chains.
One estimate places anchovies and sardines together as the most abundant fish in the ocean, comprising over 20% of total ocean fish biomass. Herrings likely also account for a substantial portion as well.
Menhadens are considered the second most abundantly caught fish in the United States after Alaskan pollock. Their enormous schools off the Atlantic and Gulf coasts form a vital part of coastal marine ecosystems.
Mackerels, jacks, and tunas are also found in prolific numbers as predatorsnear the top of pelagic food chains. They help regulate populations of smaller prey fish and zooplankton.
Threats and Conservation
Most common ocean fish like herring, sardines, anchovies, and menhadens are currently fished at sustainable levels in many regions. However, their populations can fluctuate widely due to environmental conditions and fishing pressures. Overfishing caused collapses of sardines, anchovies, and some herring populations in the past before management improved.
Maintaining an ecological balance while supporting commercial fisheries remains a challenge. Conservation efforts focus on preventing overfishing, protecting critical habitat, monitoring population trends, and reducing bycatch impacts. Proper management of schooling species is crucial for supporting healthy, productive marine ecosystems and economies.
Conclusion
While the oceans contain a huge diversity of fish, a select group of abundant schooling species comprise the bulk of ocean fish biomass. Herrings, sardines, anchovies, and menhadens are ecologically vital small prey fish that occur in massive numbers and convert plankton into food for larger predators. Jacks, mackerels, and tunas also rank among the most common predatory fish in tropical and temperate seas. Careful stewardship of widely distributed fish stocks is essential for supporting productive marine food webs and sustainable fisheries that provide nutrition for billions globally. Understanding the most common and ecologically crucial ocean fish provides guidance for responsible use and conservation of these vitally important living marine resources.