Fisheries
This equation describes how to calculate population size from mark-recapture data.
Ntotal = (Ntagged * Nsampled) / Nrecaptured
These are the two main methods for mitigating invasive species.
1. Reduce rates of introduction
2. Eradicate invaders
In conceptualizing marine reserves as metapopulations, we attribute this amount of harvesting in each of the patches.
No harvesting (each patch = reserve; matrix = harvested)
This ecological pattern was shown to be consistent regardless of human harvesting inside and outside of a marine reserve in Chile.
Body size-abundance distributions. This occurred despite individual taxa changing their body size-abundance relationship between both habitats.
Using catch-per-unit-effort (CPUE) is not always an effective method for estimating fisheries sizes for these two reasons.
1. A fisherman's efficiency will likely increase through time (better tech, more experience)
2. Fishermen are likely to move to new, locally abundant areas to fish (therefore meaning CPUE is not capturing fishery-wide heterogeneity)
Under these circumstances, an invasion can be considered "natural"
When a species expands its range into formerly uninhabited regions.
In order for a metapopulation to persist, these metrics need to be greater than or equal to 1.
N* or P-e/c
(N* = equilibrium population)
(P = # patches, c = colonization rate, e = extinction rate)
The three measures of biodiversity, distinguished by Greek-letter names, are distinct along this axis.
Space;
1. alpha = local site diversity
2. beta = differences between local sites (turnover)
3. gamma = regional diversity
This specific value is a well-known target for fisheries management scientists - it's the point where the model prediction and the 1:1 line are maximized.
The Maximum Sustained Yield (where the slope of the function = 1).
Invasions can occur through intentional human means (i.e. aquarium animals), or through these less direct mechanism.
1. Introduction through 'hitchhiking' on other taxa
2. Unintentional intake in transportation vectors (boat hulls, ballast water)
The strongest responses of species to protection by reserves occurs in species with these characteristics.
1. Harvested species
2. Sessile species
3. Those not with a well-managed fishery harvest
This is the equation describing the flux in species richness on an island under the theory of island biogeography.
dS/dt = c*(Sregion - S) - e*S
These are three shortcomings of Ricker models in fisheries management.
1. K can change over time and space
2. K may not exist
3. Size or age structure may modify r
4. Growth lags, etc might contribute to inaccurate estimates of r
These are two examples of unresolved issues when it comes to determining the efficacy of marine reserves.
1. Difficulty in understanding dispersal (hard to measure)
2. Effects of altered size structure
3. Effects on associated species
4. Whether or not reserves will be self-supporting as populations outside of it decline
5. Unknown effects of placement geometry
Gene flow and species turnover follow patterns of these two major factors in coastal ecosystems on the west coast of North America (and elsewhere!).
Current systems (meso-scale and larger) and latitudinal gradients in temperature.
Size-selective harvesting has shown genetic effects on alleles related to this life history phenomenon. Provide an example.
Age of maturation; this is related to whether or not the form of fishing was size-selective. Size-selective methods of salmon fishing showed selection against late maturation (Vgll3*LL) gene, while non-size-selective harvesting showed selection against Vgll3*EE gene.
Source and sink habitats need to be related in this way in order for sinks to effectively 'rescue' sources following catastrophe
Not positively correlated (i.e. decreases in sinks =/= decreases in sources)
The out-of-the-tropics model posits that regional differences in species abundance are a result of these three fundamental factors. Please include the region where these processes would be greatest in your answer.
1. Origination (highest in tropics)
2. Extinction (highest in extratropics)
3. Immigration (highest into extratropics)