IB ESS HL 4.3.8 Mitigation Strategies Topic Practice

Increased marine capture/overfishing because:
a. Increased population increasing the demand for food;
b. Increased demand in fish by consumers (because it fashionable/healthy);
c. Increased use of fish for animal feed/aquaculture;
d. Increased of subsidies/economic incentives to promote more fishing;
e. More intensive/unsustainable fishing technologies / e.g. long-lines/trawling/gill nets/satellite imaging;
f. reduced MSY due to lower reproductive potential/dwindling fisheries (positive feedback of past fishing pressure);

Example Strategy:
a. Use quotas/fish at/below maximum sustainable yield;

Strengths [2 max]:
b. Setting quotas below maximum sustainable yield reduces the amount of fish caught;
c. Allows fisheries re-stocking/gives time for fish to breed;
d. Forces regular data collection allowing informed management decisions;

Weaknesses [2 max]:
e. Difficult/expensive to monitor or enforce quotas/types of fishing gear/no fishing zones;
f. Difficult to estimate MSY / If MSY is overestimated the stock will be overfished;
g. MSY ignores system complexity/role of the organism;

Conclusion example:
Although marine protected areas can be difficult to monitor, if done successfully it promotes biodiversity and increases fish stocks.

Example Strategy:
h. Restrict types and sizes of fishing gear/mesh sizes;

Strengths [2 max]:
i. Allows fisheries re-stocking/gives time for fish to breed;
j. Having larger mesh sizes allows young fish to escape;
k. Decreases bycatch/capture of non-target species;
l. No trawling decreases habitat destruction;

Weaknesses [2 max]:
m. Difficult to enforce and monitor on the sea;
n. Larger mesh size may still allow bycatch of larger species;
o. Might decrease income for fishermen;

Conclusion example:
Gear restrictions are an important tool in protecting small fish and fragile habitats, however, they are incapable of controlling the quantity of fishing effort or the total catch.