ITQs confer stewardship incentives, ultimately changing behaviour by reducing competition among fishers. Each individual owns a known fraction of the total resource and if anyone wants to fish more than their quota they have to buy quota from other fishers.

Individual transferable quotas (ITQs) are also known as catch shares. They assign an exclusive but transferrable right to a set portion of the total allowable catch (TAC) of fish. ITQs give each individual a right and a stake in the “commons” or the fishery. (Review what tragedy of the commons is here).

DEGRADED ECOSYSTEMS When too many fish are taken out of the ocean it creates an imbalance that can erode the food web and lead to a loss of other important marine life, including vulnerable species like sea turtles and corals.

An Individual Transfer Quota (ITQ) is a quota imposed on individuals or firms by a governing body that limits the production of a good or service. If the holder of a quota does not produce the maximum amount as set out by the quota, they may transfer the remaining portion to another party.

The total allowable catch (TAC) is a catch limit set for a particular fishery, generally for a year or a fishing season. TACs are usually expressed in tonnes of live-weight equivalent, but are sometimes set in terms of numbers of fish. Source Publication: Review of Fisheries in OECD Countries: Glossary, February 1998.

Quotas are used by many countries to manage shared fish stocks. They determine how many fish of each species each country’s fleets are allowed to catch. The EU’s Common Fisheries Policy (CFP) sets quotas among EU member states, and similar deals are negotiated with neighbouring countries.

How do they work? Part of the catch—or a share—of a species is allocated to individual fishermen or groups. Each holder of a catch share must stop fishing when he reaches his limit. In most cases, fishermen can buy/sell or lease shares in a given year.

Now we can add another bête noire to the list: fishing subsidies. The majority of these taxpayer subsidies — around $20 billion — contribute to overfishing by making it artificially cheap to hunt for fish. That enables bigger trawlers to fish the ocean for longer, stressing fish populations beyond what’s sustainable.

Catch-share and co-management systems are when communities have developed allotment and enforcement systems for controlling fish catches in which each fishers gets a share of the total allowable catch. i. They can help to sustain fisheries and jobs in many communities for hundreds to thousands of years.

Protecting marine biodiversity is challenging because it is difficult to monitor the impact of the human ecological footprint, oceans are unseen by most people, oceans are often thought to be inexhaustible resources, and most of the ocean area lies outside of the jurisdiction of any nation.

Agroforestry provides many examples of reconciliation ecology at work. In tropical agroforestry systems, crops such as coffee or fruit trees are cultivated under a canopy of shade trees, providing habitat for tropical forest species outside of protected areas.

What are three ways in which projected climate change could threaten aquatic biodiversity? Average sea levels have risen, increased carbon dioxide level, and warming of the oceans.

Factors that affect aquatic ecosystems include water flow rate, salinity, acidity, oxygen, light levels, depth, and temperature. Light levels affect photosynthesizing plants and predation.

Temperature is also important because of its influence on water chemistry. Warm water holds less dissolved oxygen than cool water, and may not contain enough dissolved oxygen for the survival of different species of aquatic life. Some compounds are also more toxic to aquatic life at higher temperatures.

Increases in water temperatures as a result of climate change will alter fundamental ecological processes and the geographic distribution of aquatic species. Populations of aquatic organisms are sensitive to changes in the frequency, duration, and timing of extreme precipitation events, such as floods or droughts.

Ecosystems, the interactive system of living and nonliving organisms in a specific location, change slowly over time. When new plants and animals arrive in an area, they either thrive or struggle. Thriving species sometimes displace native species. When this happens, the system as a whole begins to change.

Hairston’s lab studies how individual species, food webs, and whole ecosystems are altered when the environment changes. One way that some freshwater organisms respond to environmental change is to evolve rapidly. The shorter the generation time, the faster this evolutionary change can occur.

Wetlands, rivers, lakes, and coastal estuaries are all aquatic ecosystems—critical elements of Earth’s dynamic processes and essential to human economies and health. Wetlands connect land and water, serving as natural filters, reducing pollution, controlling floods, and acting as nurseries for many aquatic species.