scholarly journals What determines “suitable habitat” for metapopulation studies? An analysis of environmental gradients and species assemblages in xeric forest openings

2012 ◽  
Vol 99 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Michael K. Delong ◽  
David J. Gibson
Keyword(s):  
Environmental Gradients ◽  
Species Assemblages ◽  
Suitable Habitat ◽  
Forest Openings

Residency and behavioural rhythmicity of ballan wrasse (Labrus bergylta) and rays (Raja spp.) captured in Portelet Bay, Jersey: implications for Marine Protected Area design

2012 ◽  
Vol 93 (5) ◽  
pp. 1407-1414 ◽  
Author(s):  
G.M. Morel ◽  
J. Shrives ◽  
S.F. Bossy ◽  
C.G. Meyer
Keyword(s):  
Protected Area ◽  
Marine Protected Area ◽  
Species Assemblages ◽  
Seasonal Patterns ◽  
Suitable Habitat ◽  
Fish Movements ◽  
Individual Fish ◽  
Labrus Bergylta ◽  
Species Specific

We monitored the long-term residency of reef-associated ballan wrasse and sand-dwelling rays captured at the site of a potential future Marine Protected Area (MPA: Portelet Bay, Jersey) by implanting them with small transmitters and deploying underwater receivers inside the bay. Individual fish were detected at Portelet Bay for up to 618 days, but there were species-specific differences in residency and detection patterns. Ballan wrasse were year-round residents at the study site where they exhibited distinct, rhythmic, diel, tidal and seasonal patterns of behaviour, whereas rays were occasional visitors to Portelet Bay with no discernible pattern to their visits. Results indicate relatively small MPAs (<0.5 km2) that with suitable habitat could provide effective, long-term protection for ballan wrasse, but would likely be of little conservation benefit for rays. Our findings emphasize the importance of quantifying fish movements when planning MPAs which intend to protect multi-species assemblages of coastal fishes.

Predicting bycatch hotspots based on suitable habitat derived from fishery-independent data

2020 ◽  
Vol 641 ◽  
pp. 159-175
Author(s):  
J Runnebaum ◽  
KR Tanaka ◽  
L Guan ◽  
J Cao ◽  
L O’Brien ◽  
...  
Keyword(s):  
Habitat Suitability ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Gulf Of Maine ◽  
Homarus Americanus ◽  
Management Tool ◽  
American Lobster ◽  
Suitable Habitat ◽  
Climate Conditions ◽  
Suitability Index

Bycatch remains a global problem in managing sustainable fisheries. A critical aspect of management is understanding the timing and spatial extent of bycatch. Fisheries management often relies on observed bycatch data, which are not always available due to a lack of reporting or observer coverage. Alternatively, analyzing the overlap in suitable habitat for the target and non-target species can provide a spatial management tool to understand where bycatch interactions are likely to occur. Potential bycatch hotspots based on suitable habitat were predicted for cusk Brosme brosme incidentally caught in the Gulf of Maine American lobster Homarus americanus fishery. Data from multiple fisheries-independent surveys were combined in a delta-generalized linear mixed model to generate spatially explicit density estimates for use in an independent habitat suitability index. The habitat suitability indices for American lobster and cusk were then compared to predict potential bycatch hotspot locations. Suitable habitat for American lobster has increased between 1980 and 2013 while suitable habitat for cusk decreased throughout most of the Gulf of Maine, except for Georges Basin and the Great South Channel. The proportion of overlap in suitable habitat varied interannually but decreased slightly in the spring and remained relatively stable in the fall over the time series. As Gulf of Maine temperatures continue to increase, the interactions between American lobster and cusk are predicted to decline as cusk habitat continues to constrict. This framework can contribute to fisheries managers’ understanding of changes in habitat overlap as climate conditions continue to change and alter where bycatch interactions could occur.

Decreasing water pressure cues ‘bailout’ in seaweed-associated crustaceans

2020 ◽  
Vol 653 ◽  
pp. 121-129
Author(s):  
RB Taylor ◽  
S Patke
Keyword(s):  
Water Pressure ◽  
Rapid Change ◽  
Brown Seaweed ◽  
Model System ◽  
Rate Of Change ◽  
Suitable Habitat ◽  
Changing Light ◽  
Surface Increase ◽  
Reduced Water ◽  
Transparent Chamber

Small mobile crustaceans are abundant on seaweeds. Many of these crustaceans rapidly abandon their host if it is detached from the seafloor and floats towards the surface, but the trigger for this ‘bailout’ behaviour is unknown. We tested 2 potential cues, i.e. rapid change in light and rapid change in water pressure, using >1 mm epifauna on the brown seaweed Carpophyllum plumosum as a model system. Bailout occurred in response to reduced water pressure, but not to changing light, as (1) bailout occurred at similar rates in light and dark, (2) bailout occurred on the seafloor when water pressure was reduced within a transparent chamber by the equivalent of ~0.5 m depth or more, and (3) little bailout occurred when water pressure was held constant within the chamber while seaweeds were raised to the surface. Increase in pressure (simulating sinking) did not induce bailout. The rate of bailout increased with increasing magnitude of pressure reduction but was not influenced greatly by the rate of change of pressure within the range tested (up to an equivalent of 0.4 m depth s-1). The use of pressure rather than light as a cue for bailout is consistent with the need for seaweed-associated crustaceans to rapidly abandon a detached host and relocate to suitable habitat during both day and night.

Drivers of diversity gradients of a highly mobile marine assemblage in a mesoscale seascape

2020 ◽  
Vol 638 ◽  
pp. 149-164
Author(s):  
GM Svendsen ◽  
M Ocampo Reinaldo ◽  
MA Romero ◽  
G Williams ◽  
A Magurran ◽  
...  
Keyword(s):  
Environmental Gradients ◽  
Regression Tree ◽  
Demersal Fish ◽  
Open Ocean ◽  
Shared Resources ◽  
Thermal Front ◽  
Boosted Regression Tree ◽  
Diversity Gradients ◽  
Α Diversity ◽  
Bottom Depth

With the unprecedented rate of biodiversity change in the world today, understanding how diversity gradients are maintained at mesoscales is a key challenge. Drawing on information provided by 3 comprehensive fishery surveys (conducted in different years but in the same season and with the same sampling design), we used boosted regression tree (BRT) models in order to relate spatial patterns of α-diversity in a demersal fish assemblage to environmental variables in the San Matias Gulf (Patagonia, Argentina). We found that, over a 4 yr period, persistent diversity gradients of species richness and probability of an interspecific encounter (PIE) were shaped by 3 main environmental gradients: bottom depth, connectivity with the open ocean, and proximity to a thermal front. The 2 main patterns we observed were: a monotonic increase in PIE with proximity to fronts, which had a stronger effect at greater depths; and an increase in PIE when closer to the open ocean (a ‘bay effect’ pattern). The originality of this work resides on the identification of high-resolution gradients in local, demersal assemblages driven by static and dynamic environmental gradients in a mesoscale seascape. The maintenance of environmental gradients, specifically those associated with shared resources and connectivity with an open system, may be key to understanding community stability.

Studi Histokimia Usus Biawak Air (Varanus salvator bivittatus) (Reptil: Varanidae)

2019 ◽  
Author(s):  
Mahfud Mahfud ◽  
Ernawati
Keyword(s):  
Tissue Sample ◽  
Histological Section ◽  
Tissue Perfusion ◽  
Intestinal Wall ◽  
Biological Information ◽  
Suitable Habitat ◽  
Monitor Lizard ◽  
Varanus Salvator ◽  
Hematoxylin Eosin ◽  
Paraffin Method

Biological information, behaviour and suitable habitat of water monitor was very less in order to support its maintenance management and breeding efforts. One of important information is the information of digestive tract, particularly the information about the structure of intestine tissue of water monitor. Sample in this research was intestine organ of water monitor. The animal was anesthetized, exanguinated, and fixed in paraformaldehyde 4% by tissue perfusion method. The intestine tissue sample for histological section with paraffin method was cutted with 3-4 μm thick and coloured with hematoxylin eosin (HE). Observation were performed to the structure of intestine histology. The results was analysed descriptively and presented in figures. Monitor lizard intestine consist of small intestine and large intestine. The small intestinal wall was observed similar to jejunum and ileum. The large intestinal wall was composed of transitional ephytelia and connective tissue. However, the ephytelial layer in this tissue was composed of transitional ephytelia that similar to vesica urinaria and there are no villi.

Vegetation structure and environmental gradients in the Sallum area, Egypt

2005 ◽  
Vol 31 (1) ◽  
pp. 15-32 ◽  
Author(s):  
Fawzy M. Salama ◽  
Monier Abd El-Ghani ◽  
Salah El Naggar ◽  
Khadija A. Baayo
Keyword(s):  
Vegetation Structure ◽  
Environmental Gradients

Geospatial information informs bonobo conservation efforts

2018 ◽  
Author(s):  
Janet Nackoney ◽  
Jena Hickey ◽  
David Williams ◽  
Charly Facheux ◽  
Takeshi Furuichi ◽  
...  
Keyword(s):  
Spatial Data ◽  
Pan Paniscus ◽  
Democratic Republic Of Congo ◽  
Conservation Strategies ◽  
Suitable Habitat ◽  
Community Based ◽  
Geospatial Information ◽  
République Démocratique Du Congo ◽  
Nous Montrons ◽  
Dynamic Conservation

The endangered bonobo (Pan paniscus), endemic to the Democratic Republic of Congo (DRC), is threatened by hunting and habitat loss. Two recent wars and ongoing conflicts in the DRC greatly challenge conservation efforts. This chapter demonstrates how spatial data and maps are used for monitoring threats and prioritizing locations to safeguard bonobo habitat, including identifying areas of highest conservation value to bonobos and collaboratively mapping community-based natural resource management (CBNRM) zones for reducing deforestation in key corridor areas. We also highlight the development of a range-wide model that analysed a variety of biotic and abiotic variables in conjunction with bonobo nest data to map suitable habitat. Approximately 28 per cent of the range was predicted suitable; of that, about 27.5 per cent was located in official protected areas. These examples highlight the importance of employing spatial data and models to support the development of dynamic conservation strategies that will help strengthen bonobo protection. Le bonobo en voie de disparition (Pan paniscus), endémique à la République Démocratique du Congo (DRC), est menacé par la chasse et la perte de l’habitat. Deux guerres récentes et les conflits en cours dans le DRC menacent les efforts de conservation. Ici, nous montrons comment les données spatiales et les cartes sont utilisées pour surveiller les menaces et prioriser les espaces pour protéger l’habitat bonobo, inclut identifier les zones de plus haute valeur de conservation aux bonobos. En plus, la déforestation est réduite par une cartographie collaborative communale de gestion de ressources dans les zones de couloirs essentiels. Nous soulignons le développement d’un modèle de toute la gamme qui a analysé un variété de variables biotiques et abiotiques en conjonction avec les données de nid bonobo pour tracer la carte d’un habitat adéquat. Environ 28 per cent de la gamme est prédit adéquat; de cela, environ 27.5 per cent est dans une zone officiellement protégée. Ces exemples soulignent l’importance d’utiliser les données spatiales et les modèles pour soutenir le développement de stratégies de conservations dynamiques qui aideront à renforcer la protection des bonobos.

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