Marine Zoology & Ecology: Marine Conservation

5 major threats to marine ecosystems

pollution

coastal development/ habitat loss

climate change

introduced species

overfishing

What activities make the fishing industry diverse?

Factory fishing vessels, bottom dredging, huge nets, long hook lines, lobster pots

Name examples of industrial fishing methods.

Factory vessels, dredging ocean bottoms, large-scale nets, miles of hook lines

Why are aquatic animals important to humans?

They provide healthy food

How many people depend on fisheries and aquaculture for their livelihoods?

~600 million people

What is the global trend in aquatic animal consumption?

Consumption is increasing year on year

What happens to aquatic animals not used for direct consumption?

Used mainly for fishmeal and fish oil

What percentage of aquatic animals are used for direct human consumption?

~89%

What percentage of global fish stocks are biologically unsustainable?

~35%

What does "biologically unsustainable" mean?

Fishing pressure exceeds the stock's ability to replenish

What percentage of fish stocks are fully fished or overexploited?

~93%

What does "fully fished" mean?

Stocks are harvested at or near their maximum sustainable yield

What does "overexploited" mean?

Harvesting exceeds sustainable limits, causing stock decline

Some species driven to local extinction:

slow growing, long-lived species are most vulnerable to overexploitation

Some species driven to local extinction: example

common skate complex extirpated from Irish sea since 70's- 11 years before reproduction

Sturgeon:

critically endangered

Chinese Paddlefish

extinct

Going further to find fish:

catch per unit effort falls in existing fishing grounds- fishermen exploit new areas

increases overall emissions footprint

affects sustainability more broadly

Going deeper to find fish:

extremely slow reproduction & growth rates= vulnerable

catches increase rapidly when population found, then crash

Fishing down food web- less preferred species

tuna- become rarer

smaller species (krill)- increasingly harvest for bait, aquaculture feed & human consumption

Ecosystem services:

can change nutrient cycling, biological productivity to ocean mixing & affect other ecosystem services (tourism or 'bioinspiration')

Overexploitation: bad for marine biodiversity & business

cost more to catch annual harvest of fish than they're worth

billions lost each year due to overfishing

reduced but sustainable activities- give higher economic yield

By-Catch:

over-quote, undersized individuals of commercial species

thrown back- have variable survival rates

Bycatch: Discards ban

Eu common fisheries policy

undersized fish landed & count against quota

Does aquaculture hold answers:

human population growing to 9b in 2050

2014- aquaculture overtook wild caught fish as suppliers for human consumption

energetically inefficient

Environmental risks: aquaculture

parasites/disease

escapes (genetic contamination)

displacement of wild species/ habitat take

ecosystem modification

nutrient cycles & pulses

attractive to wild species, modifying predator-prey relationships

entanglement

disruptive 'mitigation' devices

poor reporting schedules

pollution/ resource inputs, energy, minerals

Fisheries bycatch: seabirds

1000 caught each year

Fisheries bycatch: seabirds: longlines

surface feeders

Fisheries bycatch: seabirds: submerged nets

diver entrapment

Fisheries bycatch: seabirds: why they want to prevent

unpleasant, time, damage and resource losses, public image

A way fishing damages & destroys marine habitats

Bottom trawling

Bottom trawling

homogenizes sea floor- destroy slow growing coral which are habitats for other species

Bottom trawling: Jurassic coast

banned trawler fishing

huge recovery of biodiversity

benefits of Marine Protected Areas for conservation & fishermen

Bottom trawling: Alternatives

Hand picking

trailing of disco lights to attract scallops to pots

Hand picking

Smaller scale, professional, selective, doesn't destroy seabed & habitat

What we put in

Pollution

Acidification & climate change

Noise

Eutrophication & hypoxia

What we take out

Overfishing

Habitat loss

Energy

Deep sea mining