Fish Flashcards
What did Svante Arrhenius calculate in 1896?
A doubling of atmospheric CO2 leads to a temperature increase of 4-6°C
This is called the greenhouse effect.
What methods are used to observe sea temperature?
Platforms such as satellites, gliders, drifters, buoys, ships, and models
Drilling in Antarctica and the analysis of ice archives also provide information.
What is the core of the OCLTT concept?
Thermal tolerance of fish is limited by a lack of oxygen and the capacity of the organism
This leads to impairments in reproduction, development, growth, increased mortality, and extinction.
Why are some fish adapted to cold or warm temperatures?
Thermal specialization allows fish to save energy and take advantage of low viscosity
This specialization varies from species to species and life stage.
How does ocean warming and acidification affect fish fertility?
Warming and ocean acidification affect gamete quality and narrow the temperature window for fertilization
This results in a lower fertilization rate, contributing to a decline in fish populations.
What is the main task of fisheries science?
To provide fisheries managers with advice on alternative management strategies for sustainable fisheries.
What is ‘overproduction’ in relation to fish populations?
The amount of individuals in a population that exceeds carrying capacity
This biological surplus can be harvested without reducing future productivity.
Explain the concept of ‘density-dependent mortality’.
Mortality rate increases with increasing population density
This results in a relatively constant number of offspring even if the parent population is greatly reduced.
What is the aim of a virtual population analysis (VPA)?
To determine past population sizes of fish and their mortality by analyzing catch data.
What is ‘Catch per Unit Effort’ (CPUE)?
The amount of catch per unit effort (e.g., catch per hour)
It serves as an indicator of fish stock density.
Fill in the blank: The maximum population size that an environment can sustain over the long term is called _______.
K (carrying capacity)
What does Fmsy stand for?
Fishing mortality that yields the maximum sustainable yield (MSY).
What is the Precautionary Principle in fisheries management?
A principle prioritizing the safety of fish stocks even when scientific uncertainty exists.
What is the role of ‘Recruitment’ in fisheries?
The process by which young fish move into the adult fishing age.
What is ‘Maximum Sustainable Yield’ (MSY)?
The maximum sustainable harvest of a population without endangering it.
What is the ‘Surplus Production’ concept?
The biological surplus of a population that can be harvested without compromising future productivity.
What does the term ‘Thermal Specialization’ refer to?
The adaptation of a species to a particular temperature range that optimizes its physiological processes.
What is the ‘Spawning Biomass per Recruit’ (SPR)?
The mass of offspring produced by a single recruit over its lifetime.
What is the Ecosystem Approach to Fisheries Management?
A management approach that takes into account the entire ecology to minimize effects on other species.
True or False: Density-dependent mortality means that mortality decreases as population density increases.
False
What is a ‘Replacement Line’ in fisheries management?
The line in a recruit-spawner plot that defines the number of recruits needed to replace the current Spawning Stock Biomass (SSB) under a given fishing mortality.
What is the significance of survey data in stock assessment?
Survey data is crucial for estimating fish populations and understanding their dynamics over time.
