4: Conservation In Action Across Scales and Biomes Flashcards
(15 cards)
What percentage of the mangrove population was lost between 1980 and 2005?
(and area)
20%
36,000 km2
How much has the seagrass population declined since 1879?
29%
What are the main commercial activities affecting marine ecosystems?
oil rigs, communications pipelines, offshore renewables, gas and shipping
What are the main ways shipping affects marine ecosystems?
direct impacts (e.g. collisions)
invasive species (ballast water)
pollution (noise, oil, rubbish)
What percentage of annual CO2 emission are absorbed in the oceans?
25%
How much CO2 has been disposed of in the seas sonce the industrial revolution?
530 billion tons
What is ocean acidification?
Co2 reacts with water to produce carbonic acid
What are the effects of ocean acidification?
reduces pH
reduces the amount of carbonate available to calcifying marine organisms - important to coral and phytoplankton
The current biomass is what percentage lower than in the absence of fisheries expliotation?
99.2%
By-catch
large numbers of non-target species are routinely caught - mainly invertibrates
When is the maximum sustainable yield attained ?
at around 50% of virgin / unexplioted biomass
What is TAC?
Total allowable catches - Set total limit on amount of a population that can be caught, aiming for MSY
Can be divided into Individual Quotas, which limit the catch of individual boats - all IQs will sum to TAC
Transferable quotas can be traded between boats
Allocation of quotas between countries / vessels is the source of many international fisheries disagreements
Effort control
Limits can be on number, size or power of boats, types of fishing gear that are allowed
What are marine protected areas?
Areas set aside for long term conservation aims
What are the 5 features of an effective MPA?
No take
Enforced
Old
Large
Isolated
(NEOLI)
