What are fish?

Fish also known as paraphyletic are a group of organisms that consist of all gill-bearing, aquatic living, craniate (hard bone or cartilage skulled) animals that lack limbs with digits. Most fish are ectothermic (“cold-blooded”), allowing their body temperatures to vary as current temperatures change, though some of the large active swimmers like white shark and tuna can hold a higher core temperature. Fish are abundant in most bodies of water. They can be found in nearly all aquatic environments, from high mountain streams, to the abyssal and even hadal depths of the deepest oceans.

The fish (paraphyletic) class can be broken down in to 5 classes:

  • Agnatha (jawless fish)
  • Chondrichthyes (cartilaginous fish)
  • Placodermi (armoured fish)
  • Acanthodii (spiny sharks)
  • Osteichthyes (bony fish)

Because fish live underwater they are more difficult to study than terrestrial animals and plants, and information about fish populations is often lacking. But as fish are a vital resource for humans (especially as food.), other predatory species, they are also caught by recreational fishers, kept as pets, raised by fish keepers, and exhibited in public aquariums. Fish have had a role in culture through the ages, regarded as a divine being, religious symbols, and as the subjects of art, books and movies and facilitate certain ecosystem services and processes worldwide so certain regulations should be established to ensure the sustainability of such ecosystems and species.

The effects on fish populations and their solutions:

  • Over fishing – regulate fishing in known spawning areas; establish no-take-zones to allow for over spill (larger individuals will be caught as the smaller species which have not had a chance to repopulate remain within the no-take-zone improve genetic diversity); Implement registration fees for fishermen to prevent non native fishermen fishing in local waters.
  • Habitat destruction (building of dams, water pollution, water removal, direct destruction of coral reefs) – regulate dam building by assessing the ecological and economical costs and benefits; implement a tax on boat that expel large amounts of pollution or establish a carbon allowance for each registrant; reduce water removal by regulating an amount per year; Fine destructive fishing practices such as; Dynamite fishing, anchoring on reefs, cyanide fishing. establish mooring buoys.
  • Invasive species – remove when sighted invasive species as usually they have no present predators and will kill off native species

Ecosystem benefits

Fish have many different ecosystem benefits to offer starting with their importance as a food source for many other species (terrestrial, aquatic and marine) as juveniles and adults. Their existence provides a constant food source for large predatory fish to minute nudibranch that graze the algae and detritus (includes fish excrement, broken down plant matter)  from rocks. Scavenger fish remove decaying organic matter from the ecosystem improving the water quality.

Human benefits

Fish have become a huge part in the infrastructure of human civilization predominantly as a food source of which we utilize many different species of fish. We loved fish so much we developed their capture into a sport ‘Angling’ both in lakes and on the open ocean. They are bought for aesthetic purposes in aquariums and home run fish tanks. Fish scales have been artificially altered and used to make pearls, other parts of fish are used to make glue, as a nutrient additive for animal food and oil is extracted from them to make vitamin pills.

This is a continual project so our website will be regularly updated with new information and species, so be patient as some areas of the website may be incomplete.

If you have any pictures or information from or about the island please help us to improve our database by sending your information through to us via our contact page