Microhabitat-scale influences of resources and refuge on habitat selection by an estuarine opportunist fish

Alofs, Karen M.; Polivka, Karl M.

doi:10.3354/meps271297

Cited by 17 publications

(44 citation statements)

References 40 publications

(55 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The behavior of cottids is much simpler than that of mammals in the examples cited above; rather than select between a foraging patch and a refuge, cottids remain cryptic and inactive which is analogous to vigilance because there is no intake of energy by foraging. Furthermore, the intensity of foraging decreases with increasing predation risk as measured by using GUDs [9,28]; thus foraging cottids appear to trade foraging opportunities for vigilance from predation. Here, I use condition data obtained during studies of cottids in two different study systems to examine whether a strong food and safety trade-off is correlated with reduced condition variability, a result previously observed for one cottid species in one of the study systems [28].…”

Section: Introductionmentioning

confidence: 99%

“…In the estuary, food resources are abundant such that, at the patch scale, the behavioral alternatives for fish are foraging or vigilance [9,28]. Short-term experiments showed the effects of predators [9,28] and competitors [30] on growth and GUDs in estuarine individuals; thus the opportunity exists to examine these data for effects on variability in condition. Field-based experimental manipulations require the assumption that the behavior being manipulated is the substitution of vigilance for foraging because small-scale experiments do not offer the opportunity to establish two distinct habitat types for selection by foragers.…”

Section: Introductionmentioning

confidence: 99%

“…Quantification of patch use and foraging costs using GUDs is tractable for benthic fishes, especially within the family Cottidae [9,28,29]. Cottids primarily consume benthic macroinvertebrates whose density at small patches can be measured in context of consumption by fish, correcting for renewal by immigration from other patches.…”

Section: Introductionmentioning

confidence: 99%

“…In an estuarine/tidal creek study system, predationdependent foraging can affect the variability of a condition index commonly used in fisheries biology [28]. In the estuary, food resources are abundant such that, at the patch scale, the behavioral alternatives for fish are foraging or vigilance [9,28].…”

Section: Introductionmentioning

confidence: 99%

“…Field-based experimental manipulations require the assumption that the behavior being manipulated is the substitution of vigilance for foraging because small-scale experiments do not offer the opportunity to establish two distinct habitat types for selection by foragers. Given the foraging ecology of cottids, this is a valid assumption and these experiments have proven tractable for the measurement of GUDs [9] and condition variation [28]. A set of experiments dealing with foraging in the presence or absence of predation risk [9] yielded growth rates from which I calculate variability among individuals in replicate field enclosures.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Responses to the Foraging/Predation Risk Trade-Off and Individual Variability in Population-Level Fitness Correlates

Polivka

2011

ISRN Ecology

View full text Add to dashboard Cite

Foraging under the influence of interspecific interactions such as competition and predation risk can have effects on the energetic reserves of the forager. Measurements of condition in species such as fish are usually correlated with individual fecundity and, hence, fitness. From work in two study systems in which predation risk regulates habitat selection and foraging behavior of benthic fishes I examined whether risk dependence led to reduced variability in fish condition. In field populations of cottid fishes, observed in an estuarine system and in the near-shore habitat of an oligotrophic lake, I found that individuals that experienced higher predation risk showed reduced variability in CI. Estuarine cottids with high food availability and substantial predation risk varied less in CI among individuals than in the associated tidal creek. In the lake, where there is considerable heterogeneity in benthic food resources, a related cottid species showed reduced variation in CI with increasing predation risk from adults. Finally, I examine my previous experiments showing that the estuarine species is limited in its use of high resource availability in estuaries by competition and predation risk. Here I found that variability in individual condition index (CI) was higher when intraspecific and interspecific competition increased and did not increase in the face of predation risk.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Responses to the Foraging/Predation Risk Trade-Off and Individual Variability in Population-Level Fitness Correlates

Polivka

2011

ISRN Ecology

View full text Add to dashboard Cite

show abstract

Estuary habitat associations for juvenile Pacific salmon and pelagic fish: Implications for coastal planning processes

Sharpe

Carr‐Harris

Arbeider

et al. 2019

Aquatic Conservation

View full text Add to dashboard Cite

Assessment of risk from industrial developments often relies on simple habitat descriptions for focal species. However, simple habitat metrics may not be accurate predictors of locations that species actually use. Understanding the nature of habitat is particularly pressing for estuaries, as they are among the most degraded ecosystems globally but provide critical rearing habitat for many species, including Pacific salmon. Canadian environmental impact assessment approaches use simple habitat‐type models to assess risk from developments and assume that different species of salmon rely on the same habitat. This study asked what combination of habitat type and biophysical covariates best predicted use of estuary habitat by juvenile salmon and two dominant small pelagic fish. Fish were sampled via purse seine throughout the Skeena River estuary (British Columbia, Canada) for 2 years across different habitat types (eelgrass, open water, sandy banks, and rocky shores). Simple habitat‐type models were compared with models with more complex biophysical variables to predict the variability in relative abundance of juvenile Chinook (Oncorhynchus tshawytscha), coho (Oncorhynchus kisutch), and sockeye (Oncorhynchus nerka) salmon, along with pelagic fish species Pacific herring (Clupea pallasii) and surf smelt (Hypomesus pretiosus). The combination of variables that best predicted abundance differed across fish species. Pelagic fish were associated with near‐shore sites, increased temperature (herring), and increased salinity (smelt). Juvenile coho and sockeye salmon (but not Chinook), were more abundant in higher turbid waters. Chinook and sockeye salmon used eelgrass habitat more frequently than other habitat types, whereas coho salmon were more abundant in areas with high macroalgae cover. Models with these variables had greater predictive power than those using habitat type alone for juvenile salmon. Simple classifications of estuary habitat currently used in environmental risk assessment may not reflect the complex nature of fish–habitat associations. Understanding biophysical factors associated with estuary fish abundance can inform management of estuary habitat to support their nursery function for important fish.

show abstract

Habitat affinity and density‐dependent movement as indicators of fish habitat restoration efficacy

Polivka

2020

Ecosphere

View full text Add to dashboard Cite

Conceptual and methodological tools from behavioral ecology can inform studies of habitat quality, and their potential for evaluating habitat restoration in conservation efforts is explored here. Such approaches provide mechanistic detail in understanding the relationship between organisms and their habitats and are thus more informative than correlations between density and habitat characteristics. Several Pacific salmon species have been the target of habitat restoration efforts for the past 2-3 decades, but most post-restoration effectiveness studies have been limited to correlative data described above. In mark-recapture assays from four different study years, the affinity of sub-yearling Chinook salmon (Oncorhynchus tschawytscha) and steelhead (O. mykiss) for stream pools restored with or created by engineered log structures was greater than that for pools without restoration, though with high interannual variability. From corresponding distribution and density data, it was clear that habitat affinity data are not always concordant with single observations of density. The same was true of the correlation between either affinity or density and physical characteristics of pools, although depth and current velocity had some explanatory power for both responses in Chinook. Movement into pools by Chinook during the assays indicated that restored pools can support more immigrants at a given density than can unrestored pools; however, no such pattern emerged for steelhead. Variation among individuals in body condition has implications for population-wide fitness, and such low variation was correlated with stronger affinity for pools in Chinook regardless of restoration status. This suggests that pools may mediate habitat-related trade-offs and that restoring them might have a positive effect on fitness. Thus affinity, immigration, and condition data give much-needed mechanistic indication of habitat selection for restored habitat via an apparent capacity increase and those potential fitness benefits. This is stronger support for restoration effectiveness than density differences alone because density data (1) may simply indicate redistribution of fish from poor to good habitats and (2) are not adequate to show correlations between restoration and positive change in traits correlated with fitness.

show abstract

Microhabitat-scale influences of resources and refuge on habitat selection by an estuarine opportunist fish

Cited by 17 publications

References 40 publications

Responses to the Foraging/Predation Risk Trade-Off and Individual Variability in Population-Level Fitness Correlates

Responses to the Foraging/Predation Risk Trade-Off and Individual Variability in Population-Level Fitness Correlates

Estuary habitat associations for juvenile Pacific salmon and pelagic fish: Implications for coastal planning processes

Habitat affinity and density‐dependent movement as indicators of fish habitat restoration efficacy

Contact Info

Product

Resources

About