scholarly journals Natural vs. fishing disturbance: drivers of community composition on traditional king scallop, Pecten maximus, fishing grounds

2015 ◽  
Vol 73 (suppl_1) ◽  
pp. i70-i83 ◽  
Author(s):  
Claire L. Szostek ◽  
Lee G. Murray ◽  
Ewen Bell ◽  
Gemma Rayner ◽  
Michel J. Kaiser
Keyword(s):  
Species Richness ◽  
Life History Traits ◽  
Benthic Communities ◽  
Significant Negative Correlation ◽  
Environmental Drivers ◽  
English Channel ◽  
Physical Disturbance ◽  
Biological Communities ◽  
System Data ◽  
Fishing Disturbance

Abstract Scallop dredging is considered to be one of the most damaging forms of fishing to benthic habitats, although these effects vary among different habitats. The present study characterizes the biological communities that occur within the spatial limits of the English Channel king scallop dredge fishery in relation to key environmental drivers [mean seabed temperature; seabed temperature range; interannual temperature variation; bed shear stress (BSS); substrate characteristics; and depth] and across a gradient of scallop dredging intensity derived from vessel monitoring system data. Dredge fishing intensity was not correlated with species richness, species diversity, or species composition. However, increasing tidal BSS had a significant negative correlation with species richness and diversity. This outcome indicates that it is not possible to demonstrate that there is an effect of scallop fishing within the current spatial limits of the king scallop dredge fishery. This may be because historical dredge fishing could have already altered the benthic communities within the area of the scallop fishery to those that are resilient to scallop dredging, or that fishing disturbance has no impact over and above natural physical disturbance within the fishery. An analysis of biological and life history traits revealed that there was no relationship between recent fishing intensity, or BSS, and the functional composition of the communities present. However, even the lowest BSS values in the present study could be considered relatively high compared with areas outside the spatial boundaries of the fishery. Two distinct habitat groups were identified, based on the environmental drivers. These two groups were largely characterized by depth: deep (western) and shallow (eastern) sites. Species with traits that increase resilience to physical disturbance were abundant across all sample sites. Management concerning the environmental impacts of the fishery is discussed in terms of the spatial footprint of the fishery and predicted recovery time-scales for the associated benthic communities.

scholarly journals Uncovering the environmental drivers of short-term temporal dynamics in an epibenthic community from the Western English Channel

2019 ◽  
Vol 99 (7) ◽  
pp. 1467-1479
Author(s):  
Elizabeth Talbot ◽  
Jorn Bruggeman ◽  
Chris Hauton ◽  
Stephen Widdicombe
Keyword(s):  
Time Series Data ◽  
Temporal Dynamics ◽  
Anthropogenic Impacts ◽  
Benthic Communities ◽  
Food Limitation ◽  
Environmental Drivers ◽  
Sediment Surface ◽  
Series Data ◽  
English Channel ◽  
Larval Recruitment

AbstractBenthic communities, critical to the health and function of marine ecosystems, are under increasing pressure from anthropogenic impacts such as pollution, eutrophication and climate change. In order to refine predictions of likely future changes in benthic communities resulting from these impacts, we must first better constrain their responses to natural seasonality in environmental conditions. Epibenthic time series data (July 2008–May 2014) have been collected from Station L4, situated 7.25 nautical miles south of Plymouth in the Western English Channel. These data were analysed to establish patterns in community abundance, wet biomass and composition, and to link any observed patterns to environmental variables. A clear response to the input of organic material from phytoplankton blooms was detected, with sediment surface living deposit feeders showing an immediate increase in abundance, while predators and scavengers responded later, with an increase in biomass. We suggest that this response is a result of two factors. The low organic content of the L4 sediment results in food limitation of the community, and the mild winter/early spring bottom water temperatures allow the benthos to take immediate advantage of bloom sedimentation. An inter-annual change in community composition was also detected, as the community shifted from one dominated by the anomuran Anapagurus laevis to one dominated by the gastropod Turitella communis. This appeared to be related to a period of high larval recruitment for T. communis in 2013/2014, suggesting that changes in the recruitment success of one species can affect the structure of an entire community.

Taxonomy and phylogeny of calcareous sponges (Porifera: Calcarea: Calcinea) from Brazilian mid-shelf and oceanic islands

Zootaxa ◽  
2017 ◽  
Vol 4311 (3) ◽  
pp. 301 ◽  
Author(s):  
FERNANDA AZEVEDO ◽  
ANDRÉ PADUA ◽  
FERNANDO MORAES ◽  
ANDRÉ ROSSI ◽  
GUILHERME MURICY ◽  
...  
Keyword(s):  
Species Richness ◽  
Morphological Characters ◽  
Oceanic Islands ◽  
Biological Communities ◽  
Calcareous Sponges ◽  
Molecular Approaches ◽  
Strategic Value ◽  
Molecular Tree ◽  
Trindade Island ◽  
Fernando De Noronha

Despite the enormous economic, scientific and strategic value of the Brazilian oceanic and mid-shelf islands (BOMIs), the biological communities of these islands are still poorly known. An example is their fauna of calcareous sponges (Porifera: Calcarea), with only six species described up to date. In the present study, we analysed the Calcinean sponges from the mid-shelf Abrolhos Archipelago and four of the five Brazilian oceanic islands (São Pedro e São Paulo Archipelago, Fernando de Noronha Archipelago, Rocas Atoll, and Trindade Island), using both morphological and molecular approaches for taxonomy. Fourteen species were found, of which 12 are new to science: Arturia trindadensis sp. nov., Borojevia tenuispinata sp. nov., B. trispinata sp. nov., Clathrina insularis sp. nov., C. lutea sp. nov., C. mutabilis sp. nov., C. zelinhae sp. nov., Ernstia citrea sp. nov., E. multispiculata sp. nov., E. rocasensis sp. nov., E. sanctipauli sp. nov., and E. solaris sp. nov. These results raised in 63% the species richness of calcareous sponges from the BOMIs. Clathrina aurea and Leucetta floridana were recollected and the former had its geographical distribution expanded. The molecular tree obtained confirmed the morphological identifications and allowed a discussion about the evolution of morphological characters, and the usefulness of some of those characters in the taxonomy of Calcinea. 

scholarly journals Can anthropic fires affect epigaeic and hypogaeic Cerrado ant (Hymenoptera: Formicidae) communities in the same way?

2016 ◽  
Vol 64 (1) ◽  
pp. 95 ◽  
Author(s):  
Ernesto Oliveira Canedo-Júnior ◽  
Rafael Gonçalves Cuissi ◽  
Nelson Henrique De Almeida Curi ◽  
Guilherme Ramos Demetrio ◽  
Chaim José Lasmar ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Recovery Time ◽  
Fire Effects ◽  
Control Area ◽  
Control Group ◽  
Ant Communities ◽  
Fire Event ◽  
Biological Communities ◽  
One Year

Fire occurrences are a common perturbation in Cerrado ecosystems, and may differently impact the local biodiversity. Arthropods are one of the taxa affected by fires, and among them, ants are known as good bioindicators. We aimed to evaluate the effect of anthropic fires on epigaeic and hypogaeic ant communities (species richness and composition) in Cerrado areas with different post-fire event recovery periods. We conducted the study in four Cerrado areas during two weeks of 2012 dry season: one unburned and three at different post-fire times (one month, one and two years). We sampled ants with pitfall traps in epigaeic and hypogaeic microhabitats. We collected 71 ant morpho-species from 25 genera. In the epigaeic microhabitat we sampled 56 morpho-species and 42 in the hypogaeic microhabitat. The area with the shortest recovery time presented lower epigaeic ant species richness (4.3 ± 2.00) in comparison to the other areas (8.1 ± 2.68 species on one year area; 10.3 ± 2.66 species on two years area; 10.4 ± 2.31 species on control area), but recovery time did not affect hypogaeic ant species richness. Regarding ant species composition, fire did not directly affect hypogaeic ant species, which remained the same even one month after fire event. However, two years were not enough to reestablish ant species composition in both microhabitats in relation to our control group samples. Our study is the first to assess anthropic fire effects upon epigaeic and hypogaeic ants communities; highlighting the importance of evaluating different microhabitats, to more accurately detect the effects of anthropic disturbances in biological communities. We concluded that ant communities are just partially affected by fire occurrences, and epigaeic assemblages are the most affected ones in comparison to hypogaeic ants. Furthermore the study provides knowledge to aid in the creation of vegetation management programs that allow Cerrado conservation.

Recurrent wildfires drive rapid taxonomic homogenization of seasonally flooded Neotropical forests

2018 ◽  
Vol 45 (4) ◽  
pp. 378-386 ◽  
Author(s):  
ANA PAULA G. DA SILVA ◽  
HENRIQUE A. MEWS ◽  
BEN HUR MARIMON-JUNIOR ◽  
EDMAR A. DE OLIVEIRA ◽  
PAULO S. MORANDI ◽  
...  
Keyword(s):  
Species Richness ◽  
Woody Species ◽  
Ecosystem Processes ◽  
Tropical Species ◽  
Neotropical Forests ◽  
Floristic Similarity ◽  
Biological Communities ◽  
Local Extinctions ◽  
Seasonally Flooded ◽  
Amazonian Forests

SUMMARYRecent evidence has shown that most tropical species are declining as a result of global change. Under this scenario, the prevalence of tolerant species to disturbances has driven many biological communities towards biotic homogenization (BH). However, the mechanisms that drive communities towards BH are not yet thoroughly understood. We tested effects of recurring wildfires on woody species richness and composition in six seasonally flooded Amazonian forests and whether these fires reduce species composition (i.e., taxonomic homogenization) over short periods of time. Our results show that these forests are undergoing taxonomic homogenization in response to recurring fire events. Species richness decreased as a result of local extinctions and floristic similarity increased among forest communities. Fire was selecting tolerant (‘winner’) species and eliminating the more sensitive (‘loser’) species. BH leads to biodiversity erosion, which can deeply alter ecosystem processes such as productivity, nutrient cycling and decomposition, resulting in important consequences for conservation.

scholarly journals Biodiversity and conservation of terricolous lichens and bryophytes in continental lowlands of northern Italy: the role of different dry habitat types

2020 ◽  
Vol 29 (13) ◽  
pp. 3533-3550
Author(s):  
Gabriele Gheza ◽  
Silvia Assini ◽  
Chiara Lelli ◽  
Lorenzo Marini ◽  
Helmut Mayrhofer ◽  
...  
Keyword(s):  
Species Richness ◽  
Vegetation Dynamics ◽  
Biodiversity Loss ◽  
Northern Italy ◽  
Environmental Drivers ◽  
Dry Grasslands ◽  
Species Of Conservation Concern ◽  
Terricolous Lichens ◽  
Landscape Scales

Abstract In dry habitats of European lowlands terricolous lichens and bryophytes are almost neglected in conservation practises, even if they may strongly contribute to biodiversity. This study aims at (a) testing the role of heathlands, acidic and calcareous dry grasslands for lichen and bryophyte diversity and conservation in lowland areas of northern Italy characterized by high human impact and habitat fragmentation; (b) detecting the effect of environmental drivers and vegetation dynamics on species richness and composition. Lichens, bryophytes, vascular plants, and environmental variables were recorded in 287 circular plots for 75 sites. Our results indicate that heathlands, acidic and calcareous dry grasslands host peculiar terricolous lichen and bryophyte communities that include several species of conservation concern. Thus, each habitat provides a complementary contribution to lichen and bryophyte diversity in continental lowland landscapes. Furthermore, in each habitat different factors drive species richness and composition with contrasting patterns between lichens and bryophytes. In terms of conservation, our results indicate that management of lowland dry habitats should act at both local and landscape scales. At local scale, vegetation dynamics should be controlled in order to avoid biodiversity loss due to vegetation dynamics and wood encroachment. At the landscape scale, patches of all the three habitats should be maintained to maximize regional diversity.

scholarly journals Bat Species Richness and Community Composition along a Mega-transect in the Okavango River Basin

Diversity ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 188 ◽  
Author(s):  
Sina M. Weier ◽  
Mark Keith ◽  
Götz G. Neef ◽  
Daniel M. Parker ◽  
Peter J. Taylor
Keyword(s):  
Species Richness ◽  
Community Composition ◽  
River Basin ◽  
Total Activity ◽  
Environmental Drivers ◽  
Conservation Strategies ◽  
Miombo Woodlands ◽  
Human Land Use ◽  
Functional Community ◽  
Okavango River

The Okavango River Basin is a hotspot of bat diversity that requires urgent and adequate protection. To advise future conservation strategies, we investigated the relative importance of a range of potential environmental drivers of bat species richness and functional community composition in the Okavango River Basin. During annual canoe transects along the major rivers, originating in the central Angolan highlands, we recorded more than 25,000 bat echolocation calls from 2015 to 2018. We corrected for possible biases in sampling design and effort. Firstly, we conducted rarefaction analyses of each survey year and sampling appeared to be complete, apart from 2016. Secondly, we used total activity as a measure of sample effort in mixed models of species richness. Species richness was highest in the Angola Miombo Woodlands and at lower elevations, with higher minimum temperatures. In total, we identified 31 individual bat species. We show that even when acoustic surveys are conducted in remote areas and over multiple years, it is possible to correct for biases and obtain representative richness estimates. Changes in habitat heterogeneity will have detrimental effects on the high richness reported here and human land-use change, specifically agriculture, must be mediated in a system such as the Angolan Miombo Woodland.

scholarly journals Sex-specific pace-of-life syndromes

2019 ◽  
Vol 30 (4) ◽  
pp. 1096-1105 ◽  
Author(s):  
Joe A Moschilla ◽  
Joseph L Tomkins ◽  
Leigh W Simmons
Keyword(s):  
Life History ◽  
Metabolic Rate ◽  
Risk Taking ◽  
Life History Traits ◽  
Significant Negative Correlation ◽  
Covariance Structures ◽  
Field Crickets ◽  
Pace Of Life ◽  
Specific Trait ◽  
Trait Covariance

Abstract The pace-of-life syndrome (POLS) hypothesis considers an animal’s behavior, physiology, and life history as nonindependent components of a single integrated phenotype. However, frequent deviations from the expected correlations between POLS traits suggest that these relationships may be context, and potentially, sex dependent. To determine whether the sexes express distinct POLS trait covariance structures, we observed the behavior (mobility, latency to emerge from a shelter), physiology (mass-specific metabolic rate), and life history (life span, development time) of male and female Australian field crickets (Teleogryllus oceanicus). Path analysis modeling suggested that POLS trait covariation differed between the sexes. Although neither sex displayed the complete integration of traits predicted by the POLS hypothesis, females did display greater overall integration with a significant negative correlation between metabolic rate and risk-taking behavior but with life-history traits varying independently. In males, however, there was no clear association between traits. These results suggest that T. oceanicus do indeed display sex-specific trait covariance structures, emphasizing the importance of acknowledging sex in assessments of POLS.

scholarly journals Defining thresholds of sustainable impact on benthic communities in relation to fishing disturbance

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
G. I. Lambert ◽  
L. G. Murray ◽  
J. G. Hiddink ◽  
H. Hinz ◽  
H. Lincoln ◽  
...  
Keyword(s):  
Benthic Communities ◽  
Fishing Disturbance

scholarly journals Predicting the effects of area closures and fishing effort restrictions on the production, biomass, and species richness of benthic invertebrate communities

2006 ◽  
Vol 63 (5) ◽  
pp. 822-830 ◽  
Author(s):  
J.G. Hiddink ◽  
T. Hutton ◽  
S. Jennings ◽  
M.J. Kaiser
Keyword(s):  
Species Richness ◽  
North Sea ◽  
Fishery Management ◽  
Benthic Communities ◽  
Fishing Effort ◽  
Management Actions ◽  
The North ◽  
The North Sea ◽  
Effort Reduction ◽  
Positive Effect

AbstractTo effectively implement an Ecosystem Approach to Fisheries (EAF), managers need to consider the effects of management actions on the fishery and the ecosystem. Methods for assessing the effects on target stocks are generally well developed, but methods for assessing the effects on other components and attributes of the ecosystem are not. Area closures and effort controls are widely used fishery management tools that affect the distribution of fishing effort and may therefore have consequences for a range of species and habitats. An approach is developed to predict the effects of area closures and effort control on the biomass, production, and species richness of benthic communities in the North Sea. The redistribution of beam trawling effort as a result of management action was modelled with a random utility model, assuming that fishers selected fishing grounds on the basis of their knowledge of past catch rates. The effects of trawling on benthic invertebrates were predicted using a size-based model that accounted for differences in habitat among fishing grounds. Our simulations demonstrated that closures of different sizes and in different locations could have positive or negative effects on benthic communities. These predicted effects resulted from the trade-off between recovery in the closed areas and additional trawling effects in the open areas that arose from displaced fishing activity. In the absence of effort controls, closure of lightly fished areas had the strongest positive effect on benthic communities. Effort reduction also had a positive effect. Therefore, area closures in lightly fished areas, coupled with effort reduction, are expected to minimize the effects of fishing on benthic communities. As it was not possible to access full international data for the North Sea beam trawl fleet, the results of the analyses are illustrative rather than complete. Nevertheless, what is demonstrated is an effective approach for assessing the environmental consequences of fishery management action that can be used to inform management decision-making as part of an EAF.

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