Nursery Habitat Quality Assessed by the Condition of Juvenile Fishes: Not All Estuarine Areas Are Equal

Marine species possess dispersive stages that interconnect subpopulations, which may inhabit ‘source’ and ‘sink’ habitats, where reproduction and emigration either exceed or fall short of mortality and immigration, respectively. Postlarval supply, juvenile density and adult abundance of the Caribbean spiny lobster, Panulirus argus, were measured at four widely separated sites spanning >100 km in Exuma Sound, Bahamas. Adult abundance was lowest at a site with the highest postlarval supply and little nursery habitat; hence, it was tentatively classified as a sink. Circulation in Exuma Sound is dominated by large-scale gyres which apparently concentrate and advect postlarvae toward the nominal sink. The remaining three sites, including one marine reserve, had higher adult abundances despite lower postlarval supply, and are therefore tentatively classified as sources. Postlarval supply is probably decoupled from adult abundance by physical transport. Adult abundance is likely decoupled from postlarval supply by the effects of varying habitat quality upon postlarval and juvenile survival, as indicated by non-significant differences among sites in juvenile density. It appears that some sites with suitable settlement and nursery habitat are sources of spawning stock for Panulirus argus, whereas others with poor habitat are sinks despite sufficient postlarval influx.

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Feeding strategies and body condition of juvenile European flounder Platichthys flesus in a nursery habitat

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315420000600 ◽

2020 ◽

Vol 100 (5) ◽

pp. 795-806

Author(s):

C. Mendes ◽

S. Ramos ◽

M. Elliott ◽

A. A. Bordalo

Keyword(s):

Age Groups ◽

Nursery Habitat ◽

Trophic Levels ◽

Feeding Strategies ◽

Nursery Ground ◽

Platichthys Flesus ◽

Nursery Habitat Quality ◽

C Value ◽

European Flounder ◽

Condition Indices

AbstractEstuarine habitats are major nurseries for the European flounder Platichthys flesus, with different year classes sharing food and space resources. Hence, an understanding of feeding strategies that optimize resource use and maintain carrying capacity is fundamental for sustainable and successful ecosystem management. The main feeding areas of juvenile European flounder (including 0-group and 1-group age classes) in the Lima estuary (northern Portugal) nursery ground were investigated by integrating stomach content analyses with stable isotopic values (δ13C and δ15N) and fish condition indices (Fulton K and RNA:DNA ratio). The 0-group flounder that were associated with the upstream section of the estuary presented the lowest δ13C value (−25.58 ± 1.86‰), while 1-group flounder exhibited a higher δ13C value (−22.59 ± 2.51‰), indicating use of the more saline areas of the estuary (lower and middle sections). The two age groups did not differ in terms of δ15N (0-group: 13.93 ± 0.29‰; 1-group: 13.50 ± 0.96‰), indicating similar trophic levels. The low salinity upper estuary was the main feeding area of 0-group flounder (74%), while 1-group flounder fed along the estuary both upstream (52%) and downstream (48%). Juvenile flounder showed high individual condition based on the Fulton K index (0-group: 1.05 ± 0.08; 1-group: 1.07 ± 0.05) and RNA:DNA (0-group: 1.70 ± 0.70; 1-group: 1.41 ± 0.47). These indices deal with fish health, and hence indicate nursery habitat quality. It is concluded that in this temperate nursery habitat, different feeding strategies sustained the condition of the European flounder juveniles, compared with other flounder populations.

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Effects of hypoxia on habitat quality of pelagic planktivorous fishes in the northern Gulf of Mexico

Marine Ecology Progress Series ◽

10.3354/meps10768 ◽

2014 ◽

Vol 505 ◽

pp. 209-226 ◽

Cited By ~ 17

Author(s):

H Zhang ◽

DM Mason ◽

CA Stow ◽

AT Adamack ◽

SB Brandt ◽

...

Keyword(s):

Gulf Of Mexico ◽

Habitat Quality ◽

Northern Gulf Of Mexico

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Current Condition of Pannonic Salt Steppes at Their Distribution Limit: What Do Indicator Species Reveal about Habitat Quality?

Plants ◽

10.3390/plants10030530 ◽

2021 ◽

Vol 10 (3) ◽

pp. 530

Author(s):

Zuzana Dítě ◽

Róbert Šuvada ◽

Tibor Tóth ◽

Pavol Eliáš Jun ◽

Vladimír Píš ◽

...

Keyword(s):

Land Use ◽

Habitat Quality ◽

Indicator Species ◽

Good Condition ◽

Central Area ◽

East Central Europe ◽

Conservation Practice ◽

Ecological Conditions ◽

Typical Habitat ◽

Priority Habitat

Little is known about the suite of ecological conditions under which characteristic species may continue to develop under the pressure of recent habitat deterioration. We aimed to determine the niche of three indicator species of the priority habitat Pannonic salt steppes and to find out how their vegetation composition, land use, and soil chemistry mirror the current condition of their typical habitat. A plot-based vegetation survey was conducted in degraded and in pristine (reference) inland salt steppes in East-Central Europe. We confirmed decreased habitat quality at their northern geographical limit. Most of the sites there showed a strong prevalence of generalists (e.g., Elytrigia repens) and lack of specialists, both resulting from lowered habitat extremity and inappropriate land use (abandonment). A small proportion of plots (19%) were in the same good condition as the reference vegetation in the central area. Soil analyses revealed that the studied halophytes are able to persist on desalinized soils if the land use is suitable. The occurrence of the annual Camphorosma annua (Amaranthaceae) was driven largely by abiotic stress; grazing alone is insufficient for its long-term persistence, while the perennial Artemisia santonicum (Asteraceae) and Tripolium pannonicum (Asteraceae) have higher survival chances as they are able to coexist with generalists. Overall habitat quality can be reliably determined from the analyzed ecological conditions of indicator species. The outcomes of the presented work are relevant for conservation practice and can serve as a quick tool for assessing the current stage of other grassland habitats.

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Multi-Scenario Analysis of Habitat Quality in the Yellow River Delta by Coupling FLUS with InVEST Model

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18052389 ◽

2021 ◽

Vol 18 (5) ◽

pp. 2389

Author(s):

Qinglong Ding ◽

Yang Chen ◽

Lingtong Bu ◽

Yanmei Ye

Keyword(s):

Land Use ◽

Land Use Change ◽

Habitat Quality ◽

Scenario Analysis ◽

Yellow River ◽

The Yellow River ◽

Cultivated Land ◽

Invest Model ◽

Unused Land ◽

Dongying City

The past decades were witnessing unprecedented habitat degradation across the globe. It thus is of great significance to investigate the impacts of land use change on habitat quality in the context of rapid urbanization, particularly in developing countries. However, rare studies were conducted to predict the spatiotemporal distribution of habitat quality under multiple future land use scenarios. In this paper, we established a framework by coupling the future land use simulation (FLUS) model with the Intergrated Valuation of Environmental Services and Tradeoffs (InVEST) model. We then analyzed the habitat quality change in Dongying City in 2030 under four scenarios: business as usual (BAU), fast cultivated land expansion scenario (FCLE), ecological security scenario (ES) and sustainable development scenario (SD). We found that the land use change in Dongying City, driven by urbanization and agricultural reclamation, was mainly characterized by the transfer of cultivated land, construction land and unused land; the area of unused land was significantly reduced. While the habitat quality in Dongying City showed a degradative trend from 2009 to 2017, it will be improved from 2017 to 2030 under four scenarios. The high-quality habitat will be mainly distributed in the Yellow River Estuary and coastal areas, and the areas with low-quality habitat will be concentrated in the central and southern regions. Multi-scenario analysis shows that the SD will have the highest habitat quality, while the BAU scenario will have the lowest. It is interesting that the ES scenario fails to have the highest capacity to protect habitat quality, which may be related to the excessive saline alkali land. Appropriate reclamation of the unused land is conducive to cultivated land protection and food security, but also improving the habitat quality and giving play to the versatility and multidimensional value of the agricultural landscape. This shows that the SD of comprehensive coordination of urban development, agricultural development and ecological protection is an effective way to maintain the habitat quality and biodiversity.

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