Capelin are small, slender fish residing in the cold, northern waters of the Atlantic, Pacific, and Arctic Oceans. These schooling fish play a significant role in the marine environment. Their abundance and distribution across vast ocean regions make them a notable component of many marine ecosystems. Understanding capelin provides insight into the intricate connections within cold-water marine food webs.
What is Capelin?
Capelin, scientifically known as Mallotus villosus, are a species of forage fish belonging to the smelt family. They measure between 13 to 25 centimeters in length. Capelin possess an elongated body, an olive-colored back, and silvery-white undersides, with gray on their sides. Their snout is pointed, and their lower jaw projects slightly forward.
These fish are pelagic, from the surface down to depths exceeding 700 meters. Capelin form large, dense schools, a behavior that offers some protection against predators. They have a short lifespan, living for two to five years. Capelin reach sexual maturity around three years of age.
Ecological Significance
Capelin hold a position as a primary forage fish, forming an important link in cold-water marine food webs. They consume zooplankton, such as copepods, krill, and other small crustaceans, converting this abundant food source into a form accessible to larger animals. This transfer of energy from lower to higher trophic levels underscores their importance in the ecosystem.
Many larger marine predators rely on capelin as a food source. These include fish like Atlantic cod, marine mammals such as whales and seals, and numerous seabird species. Fluctuations in capelin populations can therefore have cascading effects, influencing the health, growth, and reproductive success of the species that depend on them.
Human Interaction and Uses
Capelin are a commercially fished species, supporting significant fisheries in regions like Newfoundland and Labrador, Iceland, and the Barents Sea. The fish are utilized in several ways, including direct human consumption, where they can be eaten fresh, frozen, smoked, or salted. Its roe, known as masago, is used in Japanese and other Asian markets for sushi.
Beyond human consumption, capelin are processed into fishmeal and fish oil, which are used in animal feed and various industrial applications. They also serve as bait for other fisheries. The demand for capelin roe has historically led to fisheries targeting egg-bearing females, though management practices aim to reduce wastage of other parts of the catch.
Conservation and Management
Managing capelin stocks presents challenges due to their short lifespan, high reproductive potential, and sensitivity to environmental shifts. Their populations naturally exhibit boom-and-bust cycles, influenced by factors such as sea surface temperature, zooplankton availability, and larval survival rates. Overfishing can exacerbate these natural fluctuations, leading to significant declines in stock levels.
Scientific assessment and international cooperation are important to sustainable management of capelin fisheries. Fisheries authorities employ multispecies approaches to manage capelin alongside their predators, like Atlantic cod. Setting fishing quotas based on scientific advice is a primary tool for conservation, sometimes resulting in reduced or even zero quotas to allow stocks to recover. These efforts aim to protect both capelin populations and the broader marine ecosystems that depend on them.