The benthic zone is region of a body of water (lake, river, or ocean) that is near the bottom. It includes the surface and some of the sub-surface layers of the sediment. The sediment can sand, mud, rocks, coral, among other substances. Benthos are organisms living in the benthic zone. These organisms are predominately invertebrates, but the benthic community is very important to some fish species. For example, the tripod fish (Bathypterois grallator) is a deep-sea benthic fish that uses modified fins and fin rays to stand on the ocean floor and wait for prey items to approach. These fish can grow up to 3 feet long!
The littoral zone is the region of a body of water (lake, river, or ocean) that is near the shore. While there is no exact definition of the zone, in marine systems it is generally considered to extend from the high-water mark to the continental shelf; freshwater systems it is generally considered to be wetland zones where sunlight can still reach rooted plants. Because of its close association with terrestrial systems, the littoral zone is nutrient rich and highly productive. Fish in these areas, like coral reef fishes, for example, often become highly specialized feeders because of the diverse and abundant food sources.
IUU fishing is illegal, unregulated, and unreported fishing. According to the 2001 FAO International Plan of Action to Prevent, Deter and Eliminate Illegal, Unreported, and Unregulated Fishing,
Illegal fishing refers to activities:
- conducted by national or foreign vessels in waters under the jurisdiction of a State, without the permission of that State, or in contravention of its laws and regulations;
- conducted by vessels flying the flag of States that are parties to a relevant regional fisheries management organization but operate in contravention of the conservation and management measures adopted by that organization and by which the States are bound, or relevant provisions of the applicable international law; or
- in violation of national laws or international obligations, including those undertaken by cooperating States to a relevant regional fisheries management organization.
Unreported fishing refers to fishing activities:
- that have not been reported, or have been misreported, to the relevant national authority, in contravention of national laws and regulations; or
- undertaken in the area of competence of a relevant regional fisheries management organization which have not been reported or have been misreported, in contravention of the reporting procedures of that organization.
Unregulated fishing refers to fishing activities:
- in the area of application of a relevant regional fisheries management organization that are conducted by vessels without nationality, or by those flying the flag of a State not party to that organization, or by a fishing entity, in a manner that is not consistent with or contravenes the conservation and management measures of that organization; or
- in areas or for fish stocks in relation to which there are no applicable conservation or management measures and where such fishing activities are conducted in a manner inconsistent with State responsibilities for the conservation of living marine resources under international law.
While all three types of IUU fishing result from a lack of resources (to enforce, report, and regulate), lumping these three different types of fishing under one category simplifies the complex issues, linking illegal activities (i.e., illegal fishing) with legal activities (i.e., unreported and unregulated fishing). Illegal fishing is a regulatory issue; unreported and unregulated fisheries do not break any law – they are management issues, or rather a lack of management issue. IUU fishing often basks in a negative light, but this legal distinction makes it difficult to chastise fishermen just because their government lacks the capabilities to report or regulate their fishery. For more information on the challenges to managing IUU fishing, please refer to the following AFS publication:
Serdy, Andrew. 2011. Simplistic or Surreptitious? Beyond the Flawed Concept(s) of IUU Fishing. Pages 253-279 in W.W. Taylor, A.J. Lynch, and M.G. Schechter, editors. Sustainable Fisheries: Multi-Level Approaches to a Global Problem. American Fisheries Society, Bethesda, Maryland.
Ichthyology is the study of fishes*. With an estimated 27,977 species, fish are the most numerous and diverse group of vertebrate species. In fact, there are more fish species than all other groups of vertebrates (amphibians, reptiles, birds, and mammals) combined.
One could argue that people have been studying fish for the purposes of food since prehistoric times, but the scientific study of fish began in earnest during the European Renaissance. While famed taxonomist Carolus Linnaeus did identify many fish species, his colleague, Peter Artedi, is considered the “father of ichthyology” for standardizing morphometric (measurement ) and meristic (count) methods still used to classify species. According to FishBase, a comprehensive, publically accessible database of fish species , over 10 species are named in his honor.
Beginning with basic anatomy and systematics (study of evolutionary relationships among fishes), ichthyology has broadened to include ecology (study of interactions between fish and their environment), physiology (study of internal function of fish), and behavior. Ichthyology forms the foundation of fisheries science which applies the understanding of fishes in the context of fisheries (the harvest of fish and other aquatic organisms for human use).
*Note that fish is singular and plural when in reference to a single species. Fishes is plural in reference to more than one species.
Polyandry is a polygamous mating system where a female has multiple male partners during the breeding season. This is a relatively uncommon form of polygamy and has only been reported in anemonefish (Amphiprioninae) and could be the case for deep sea anglerfish (Ceratiidae). Though anemonefish are generally monogamous, polyandry has been reported in some circumstances. In Deep Sea Anglerfish, multiple males can be attached to a large female, almost in a parasitic relationship where their circulatory system merges with the female’s. See polygamous; polygyny.
Polygamous is a mating system in which an individual of one sex has multiple partners during the breeding system but individuals of the opposite sex have only one partner. Evolutionarily, these systems are purported to have an increased chance of passing on “good genes” from individuals that compete for the ability to mate with multiple partners. This mating system can occur with one male and many females (see polygyny) or one female and multiple males (see polyandry).
Promiscuous is a mating system where both sexes have multiple partners during the breeding system. In fishes, this is the most common mating system. Breeders make
little or no mate choice and spawn with multiple partners, either sequentially or at the same time.
Breeding aggregations of promiscuous spawners can make some fish species particularly vulnerable to fishing. The fish generally assemble according to environmental cues (e.g., temperature, moon phase) that are known to fishermen. Overfishing on spawning aggregations can be particularly devastating to fish populations because the high fecundity (fertility) individuals are readily removed from the population. The Nassau grouper (Epinephelus
striatus), for example, once supported an important Caribbean fishery but is currently endangered because of overfishing on these spawning aggregations.
FISH MATING STRATEGIES
In honor of Valentines Day, please enjoy the first series of post for this blog post on fish mating strategies! Check back weekly for new additions to the “Fish-ionary.”
- Promiscuous: A mating system where both sexes have multiple partners during the breeding system. In fishes, this is the most common mating system. Breeders make little or no mate choice and spawn with multiple partners, either sequentially or at the same time….read more.
- Polygamous: A mating system in which an individual of one sex has multiple partners during the breeding system but individuals of the opposite sex have only one partner…. read more.
- Polygyny: A polygamous mating system where a male has multiple female partners during the breeding season. This is the more common form of polygamy….read more.
- Polyandry: A polygamous mating system where a female has multiple male partners during the breeding season….read more.
- Monogamy: A mating system where partners live and exclusively mate with only each other….read more.
Polygyny is a polygamous mating system where a male has multiple female partners during the breeding season. This is the more common form of polygamy.
Polygynous males, like slimy sculpins (Cottus cognatus), setup territories and are visited by multiple females. Other polygynous males, like some African cichlids (such as Mchenga eucinostomus), form leks, where they congregate and perform breeding displays to attract female passers-by. And still other polygynous males, like wrasses (Labridae), form harems where a large male protects a number of females with which he, alone, can mate. See polygamous;
Monogamy is a mating system where partners live and exclusively mate with only each other. These pair bonds can be transitory, just for a single breeding season, extend for several years or even a lifetime. Fish that form strong pair bonds include: American freshwater catfish, some cichlids, and many butterflyfish. The Four-Eyed Butterflyfish (Chaetodon capistratus) is one such fish that mates for life – very rare in the fish world.