Context Dependence: A Conceptual Approach for Understanding the Habitat Relationships of Coastal Marine Fauna

BioScience ◽  
2020 ◽  
Author(s):  
Michael Bradley ◽  
Ivan Nagelkerken ◽  
Ronald Baker ◽  
Marcus Sheaves
Keyword(s):  
Salt Marshes ◽  
Tidal Range ◽  
Environmental Drivers ◽  
Spatial And Temporal Variation ◽  
Kelp Forests ◽  
Habitat Types ◽  
Conceptual Approach ◽  
Ongoing Research ◽  
Management Actions ◽  
Animal Habitat

Abstract Coastal habitats, such as seagrasses, mangroves, rocky and coral reefs, salt marshes, and kelp forests, sustain many key fish and invertebrate populations around the globe. Our understanding of how animals use these broadly defined habitat types is typically derived from a few well-studied regions and is often extrapolated to similar habitats elsewhere. As a result, a working understanding of their habitat importance is often based on information derived from other regions and environmental contexts. Contexts such as tidal range, rainfall, and local geomorphology may fundamentally alter animal–habitat relationships, and there is growing evidence that broadly defined habitat types such as “mangroves” or “salt marsh” may show predictable spatial and temporal variation in habitat function in relation to these environmental drivers. In the present article, we develop a framework for systematically examining contextual predictability to define the geographic transferability of animal–habitat relationships, to guide ongoing research, conservation, and management actions in these systems.

scholarly journals Latitudinal patterns in intertidal ecosystem structure in West Greenland suggest resilience to climate change

2021 ◽  
Author(s):  
Jakob Thyrring ◽  
Susse Wegeberg ◽  
Martin E Blicher ◽  
Dorte Krause-Jensen ◽  
Signe H&oslashgslund ◽  
...  
Keyword(s):  
Climate Change ◽  
Ascophyllum Nodosum ◽  
Tidal Range ◽  
Environmental Drivers ◽  
Small Scale ◽  
Ecosystem Structure ◽  
Assemblage Composition ◽  
West Greenland ◽  
Functional Changes ◽  
Time Substitution

Climate change has ecosystem-wide cascading effects. Little is known, however, about the resilience of Arctic marine ecosystems to environmental change. Here we quantify and compare large-scale patterns in rocky intertidal biomass, coverage and zonation in six regions along a north-south gradient of temperature and ice conditions in West Greenland (60-72°N). We related the level and variation in assemblage composition, biomass and coverage to latitudinal-scale environmental drivers. Across all latitudes, the intertidal assemblage was dominated by a core of stress-tolerant foundation species that constituted >95% of the biomass. Hence, canopy-forming macroalgae, represented by Fucus distichus subsp. evanescens and F. vesiculosus and, up to 69 °N, also Ascophyllum nodosum, together with Semibalanus balanoides, occupied >70% of the vertical tidal range in all regions. Thus, a similar functional assemblage composition occurred across regions, and no latitudinal depression was observed. The most conspicuous difference in species composition from south to north was that three common species (the macroalgae Ascophyllum nodosum, the amphipod Gammarus setosus and the gastropod Littorina obtusata) disappeared from the mid-intertidal, although at different latitudes. There were no significant relationships between assemblage metrics and air temperature or sea ice coverage as obtained from weather stations and satellites, respectively. Although the mean biomass decreased >50% from south to north, local biomass in excess of 10 000 g ww m-2 was found even at the northernmost site, demonstrating the patchiness of this habitat and the effect of small-scale variation in environmental characteristics. Hence, using the latitudinal gradient in a space-for-time substitution, our results suggest that while climate modification may lead to an overall increase in the intertidal biomass in north Greenland, it is unlikely to drive dramatic functional changes in ecosystem structure in the near future. Our dataset provides an important baseline for future studies to verify these predictions for Greenlands intertidal zone.

Benthic Habitats and the Effects of Fishing

2005 ◽  
Keyword(s):  
Fisheries Management ◽  
Large Scale ◽  
Scale Effects ◽  
Ecosystem Processes ◽  
Fishing Effort ◽  
Habitat Types ◽  
Benthic Habitats ◽  
Management Actions ◽  
Ecosystem Effects ◽  
Ecosystem Based Fisheries Management

<strong><em>Abstract. </em></strong>We review the impacts of towed gears on benthic habitats and communities and predict the consequences of these impacts for ecosystem processes. Our emphasis is on the additive and synergistic large-scale effects of fishing, and we assess how changes in the distribution of fishing activity following management action are likely to affect production, turnover time, and nutrient fluxes in ecosystems. Analyses of the large-scale effects of fishing disturbance show that the initial effects of fishing on a habitat have greater ecosystem consequences than repeated fishing in fished areas. As a result, patchy fishing effort distributions have lower total impacts on the ecosystem than random or uniform effort distributions. In most fisheries, the distribution of annual fishing effort within habitats is more patchy than random, and patterns of effort are maintained from year to year. Our analyses suggest that many vulnerable species and habitats have only persisted in heavily fished ecosystems because effort is patchy. Ecosystem-based fisheries management involves taking account of the ecosystem effects of fishing when setting management objectives. One step that can be taken toward ecosystem-based fisheries management is to make an a priori assessment of the ecosystem effects of proposed management actions such as catch controls, effort controls, and technical measures. We suggest a process for predicting the ecosystem consequences of management action. This requires information on habitat distributions, models to predict changes in the spatial distribution of fleets following management action, and models of the impacts of trawling disturbance on ecosystem processes. For each proposed management action, the change in disturbance affecting different habitat types would be predicted and used to forecast the consequences for the ecosystem. These simulations would be used to produce a decision table, quantifying the consequences of alternative management actions. Actions that minimize the ecosystem effects of fishing could then be identified. In data-poor situations, we suggest that management strategies that maintain or maximize the patchiness of effort within habitat types are more consistent with the precautionary approach than those that lead to more uniform fishing effort distributions.

Preventing local extinctions of tidal marsh endemic Seaside Sparrows and Saltmarsh Sparrows in eastern North America

The Condor ◽  
2019 ◽  
Vol 121 (2) ◽  
Author(s):  
Samuel G Roberts ◽  
Rebecca A Longenecker ◽  
Matthew A Etterson ◽  
Chris S Elphick ◽  
Brian J Olsen ◽  
...  
Keyword(s):  
New Jersey ◽  
North America ◽  
Sea Level Rise ◽  
Sea Level ◽  
Salt Marshes ◽  
Local Population ◽  
Population Persistence ◽  
Vital Rates ◽  
Saltmarsh Sparrow ◽  
Management Actions

Abstract Globally limited to 45,000 km2, salt marshes and their endemic species are threatened by numerous anthropogenic influences, including sea-level rise and predator pressure on survival and nesting success. Along the Atlantic coast of North America, Seaside (Ammospiza maritima) and Saltmarsh (A. caudacuta) sparrows are endemic to salt marshes, with Saltmarsh Sparrows declining by 9% annually. Because vital rates and factors affecting population persistence vary for both species, local estimates are necessary to best predict population persistence in response to management actions. We used a metapopulation model to estimate the population viability of the breeding Seaside and Saltmarsh sparrow populations in coastal New Jersey over a 42-yr period. We incorporated empirical data on the vital rates and abundances of these populations and simulated the effect of low (0.35 m) and high (0.75 m) levels of sea-level rise. We found that the Seaside Sparrow population persisted under both sea-level rise scenarios; however, the Saltmarsh Sparrow population reached a quasi-extinction threshold within 20 yr. Using the same framework, we modeled potential management scenarios that could increase the persistence probability of Saltmarsh Sparrows and found that fecundity and juvenile survival rates will require at least a 15% concurrent increase for the local population to persist beyond 2050. Future field research should evaluate the feasibility and effectiveness of management actions, such as predator control, for increasing Saltmarsh Sparrow vital rates in order to maintain the species in coastal New Jersey.

scholarly journals Macroinvertebrates and Microbes (Archaea, Bacteria) Offer Complementary Insights into Mine-Pit Lake Ecology

2019 ◽  
Vol 39 (3) ◽  
pp. 589-602 ◽  
Author(s):  
Melanie L. Blanchette ◽  
Richard Allcock ◽  
Jahir Gonzalez ◽  
Nina Kresoje ◽  
Mark Lund
Keyword(s):  
Water Chemistry ◽  
Environmental Drivers ◽  
Sediment Chemistry ◽  
Lake Ecosystem ◽  
Pit Lake ◽  
Lake Ecosystems ◽  
Assemblage Composition ◽  
Management Actions ◽  
Pit Lakes ◽  
Broad Objective

Abstract The broad objective of this research was to determine the environmental drivers of macroinvertebrate and microbial assemblages in acidic pit lakes. This is important because pit lake ecosystem development is influenced by prevailing environmental characteristics. Three lakes (Stockton, Kepwari, WO5H) within a larger pit-lake district in Collie, Western Australia were surveyed for spatial variability of benthic macroinvertebrate and microbe (Archaea, Bacteria) assemblage composition as well as potential environmental drivers (riparian condition, aquatic habitat, sediments, and aquatic chemistry) of assemblages. With the exception of sediment chemistry, biophysical variables were significantly different across lakes and reflected riparian condition and groundwater chemistry. Microbial assemblages in pit lakes were significantly different across lakes and correlated with water chemistry, particularly metals in Lake WO5H. However, the most abundant microbes were not readily identified beyond class, making it difficult to speculate on their ecological function. Macroinvertebrate assemblage composition and species richness were also significantly different across all lakes, and in Lake WO5H (a lake with low pH and high metal concentrations), taxa were correlated with benthic organic matter as well as water chemistry. Results indicated that despite poor water quality, input of nutrients from terrestrial leaf litter can support or augment pit lake ecosystems. This is a demonstration of the concept that connection of pit lakes to catchments can positively affect aquatic ecosystems, which can inform management actions for remediation.

Effect of nitrate supply on the facilitation between two salt-marsh plants (Suaeda salsa and Scirpus planiculmis)

2020 ◽  
Vol 13 (2) ◽  
pp. 204-212
Author(s):  
Hua Ma ◽  
Li-Juan Cui ◽  
Xu Pan ◽  
Wei Li ◽  
Yu Ning ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Plant Species ◽  
Salt Marshes ◽  
Interspecific Interactions ◽  
Stress Gradient ◽  
Interactive Effects ◽  
Suaeda Salsa ◽  
Environmental Drivers ◽  
Salt Marsh Plant ◽  
Nitrate Supply

Abstract Aims In estuarine salt-marshes, nitrate supply and soil salinity, which are known as two main environmental drivers, simultaneously affect the interspecific interactions between plant species. However, to date, their interactive effects on interspecific interactions have not been closely examined for salt-marsh plant species. Methods Juvenile plants of Suaeda salsa L. (Chenopodiaceae) and Scirpus planiculmis Fr. (Cyperaceae) were grown in rinsed river sand to conduct a greenhouse experiment with three treatment categories: interspecific interaction (mixed culture or monoculture), three salinity levels (1, 50 and 100 mmol L−1) and three nitrate levels (0.5, 5 and 10 mmol L−1). First, height and biomass of all plants were measured. Then, the growth data, relative interaction index and competitive important index of the two species were analyzed. Important Findings The interspecific interactions between S. salsa and S. planiculmis were facilitation across the salinity gradients. The promotion of S. salsa growth with high nitrate supply did not enhance the facilitative effect of the species, especially at low salinity. However, high nitrate supply significantly shifted the interspecific interactions of S. planiculmis from facilitation to competition at high salinity. Our results suggest that excessive nitrate application changes the prediction of the stress-gradient hypothesis along a salinity gradient, leading to collapse of the two species coexistence in the salt-marshes. These findings make a contribution to the understanding of how S. salsa and S. planiculmis, as well as salt-marsh communities, respond to the human modification of estuarine nutritional levels.

scholarly journals Carbon stocks of mangroves and salt marshes of the Amazon region, Brazil

2018 ◽  
Vol 14 (9) ◽  
pp. 20180208 ◽  
Author(s):  
J. Boone Kauffman ◽  
Angelo F. Bernardino ◽  
Tiago O. Ferreira ◽  
Leila R. Giovannoni ◽  
Luiz Eduardo de O. Gomes ◽  
...  
Keyword(s):  
Soil Carbon ◽  
Salt Marshes ◽  
Carbon Stocks ◽  
Tidal Range ◽  
Mangrove Forests ◽  
Evergreen Forests ◽  
Ecosystem Carbon ◽  
Soil Carbon Stocks ◽  
High Tidal Range ◽  
Ecosystem Carbon Stocks

In addition to the largest existing expanse of tropical forests, the Brazilian Amazon has among the largest area of mangroves in the world. While recognized as important global carbon sinks that, when disturbed, are significant sources of greenhouse gases, no studies have quantified the carbon stocks of these vast mangrove forests. In this paper, we quantified total ecosystem carbon stocks of mangroves and salt marshes east of the mouth of the Amazon River, Brazil. Mean ecosystem carbon stocks of the salt marshes were 257 Mg C ha −1 while those of mangroves ranged from 361 to 746 Mg C ha −1 . Although aboveground mass was high relative to many other mangrove forests (145 Mg C ha −1 ), soil carbon stocks were relatively low (340 Mg C ha −1 ). Low soil carbon stocks may be related to coarse textured soils coupled with a high tidal range. Nevertheless, the carbon stocks of the Amazon mangroves were over twice those of upland evergreen forests and almost 10-fold those of tropical dry forests.

Effect of maternal habitat, temperature and light on germination and salt tolerance of Suaeda vermiculata, a habitat-indifferent halophyte of arid Arabian deserts

2018 ◽  
Vol 28 (2) ◽  
pp. 140-147 ◽  
Author(s):  
Ali El-Keblawy ◽  
Naeema Al-Shamsi ◽  
Kareem Mosa
Keyword(s):  
Salt Tolerance ◽  
Salt Marshes ◽  
Germination Rate ◽  
Interactive Effects ◽  
Distilled Water ◽  
Habitat Types ◽  
Good Opportunity ◽  
Habitat Recovery ◽  
Saline Habitats ◽  
The Difference

AbstractHabitat-indifferent species that can grow well in both saline and non-saline soils offer a good opportunity for studying seed dormancy and salt tolerance during germination. Here, we assess interactive effects of maternal habitat and incubation conditions on salt tolerance during germination of the habitat-indifferent halophyte Suaeda vermiculata, a common perennial shrub of the arid Arabian deserts. Seeds collected from saline and non-saline habitats were germinated at six salinity levels (0–500 mM NaCl) and incubated at three temperatures and under two light regimes. Studied germination attributes were final germination, germination rate index (GRI) and germination recovery of non-germinated seeds when transferred to distilled water. The results showed insignificant difference in salt tolerance between seeds of the two habitat types at the lower salinities. At higher salinities (400 and 500 mM NaCl), germination of the saline habitat seeds was almost inhibited, but that of non-saline habitat seeds reached various levels depending on light and temperature. Both higher temperatures and darkness resulted in significant reductions of the final germination at the higher salinities. Seeds of the two habitats that did not germinate in the different treatments recovered their germination when transferred to distilled water, indicating that these seeds maintained their viability in saline solution and were able germinate upon the arrival of suitable conditions. Seeds of the two habitats germinated within 2 days at the lower salinities and GRI decreased with the increase in salinity level. Such reduction was obvious for seeds of the saline habitat. Recovery was faster for seeds of the saline habitats, especially for those incubated at higher salinities and in the dark. The difference in dormancy and germination attributes of seeds of the two habitat types reflects ecological adaptations for survival in salt marshes of arid deserts.

scholarly journals Production of mobile invertebrate communities on shallow reefs from temperate to tropical seas

2020 ◽  
Vol 287 (1941) ◽  
pp. 20201798
Author(s):  
K. M. Fraser ◽  
J. S. Lefcheck ◽  
S. D. Ling ◽  
C. Mellin ◽  
R. D. Stuart-Smith ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Human Impacts ◽  
Anthropogenic Impacts ◽  
Selection Procedure ◽  
Marine Ecosystems ◽  
Environmental Drivers ◽  
Kelp Forests ◽  
Food Web Structure ◽  
Continental Scale ◽  
Biogenic Habitat

Primary productivity of marine ecosystems is largely driven by broad gradients in environmental and ecological properties. By contrast, secondary productivity tends to be more variable, influenced by bottom-up (resource-driven) and top-down (predatory) processes, other environmental drivers, and mediation by the physical structure of habitats. Here, we use a continental-scale dataset on small mobile invertebrates (epifauna), common on surfaces in all marine ecosystems, to test influences of potential drivers of temperature-standardized secondary production across a large biogeographic range. We found epifaunal production to be remarkably consistent along a temperate to tropical Australian latitudinal gradient of 28.6°, spanning kelp forests to coral reefs (approx. 3500 km). Using a model selection procedure, epifaunal production was primarily related to biogenic habitat group, which explained up to 45% of total variability. Production was otherwise invariant to predictors capturing primary productivity, the local biomass of fishes (proxy for predation pressure), and environmental, geographical, and human impacts. Highly predictable levels of epifaunal productivity associated with distinct habitat groups across continental scales should allow accurate modelling of the contributions of these ubiquitous invertebrates to coastal food webs, thus improving understanding of likely changes to food web structure with ocean warming and other anthropogenic impacts on marine ecosystems.

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