Deep water coral reefs

Basic facts:

• Can be found in water where sunlight doesn’t reach them

• Also cold cold water coral reefs, although some can be found in shallow or warm water

• Lack sunlight to support photosynthetic algae within coral polyps

Lophelia Pertusa- deep water coral species

• Found in every ocean beside polar regions

• Has been found 2 miles deep in the Atlantic

• More than 850 species rely on them in north east Atlantic

• Provide habitats for worms, fish, crustaceans, sponges and anemones

Ecological features: feeding

• Don’t have symbiotic algae

• Mush less food energy

• Grow slowly

Ecological features: slow growth

• Due to less food energy- corals grow much slower

• This means they are much more threatened by damage as they recover much more slowly

Ecological features: slow growth and reproduction of associated species

• Species associated with deep water corals are also slow growing

• Means they are threatened by over exploitation- its much more likely that fishing will be above the MSY (maximum sustainable yield, catch is above growth rate

Importance

Only been discovered since 1970’s wish many found since 2010

• Little time for research into importance, ecological roles and resources they may contain

Support a large biomass of fish, often slow- growing species with low reproductive rates

• Easy to over exploit the populations

The roundnose grenadiers blue whiting and orange roughy are fished commercially

• The orange roughy wasn’t exploited until 1980s but by 1990s catch was declining because population had been overexploited above the MSY. Fishing of populations is now banned tho allow recovery

Threats: expansion of oil and gas industry

Description:

• Increasing demand for oil and depleting reserves means that deep water oil exploitation is becoming increasingly viable

Consequences:

• Oil spills disrupt breeding cycles and spills and methods clean up mess are toxic to coral polyps

Threats: ocean acidification

Description:

• increased carbon dioxide in the atmosphere is dissolving into oceans, caused by combustion of fossil fuels

Consequences:

• pH is reduced, causes limestone structure to dissolve

Conservation: Protected areas

• Marine conservation zones, SACs, can be established to protect the habitats from damaging activities

• E.g. Darwin Mounds, SAC off north west coast of scotland

Conservation: Controlling damaging activities

• Fishing efforts can be controlled by legislations- EU CFP

• E.g. no take zones, closed seasons, minimum catchable size, quota