Macrofauna community patterns in a Chiloe Island channel used intensely for aquaculture: the ecological status of its benthic environment

Abstract Background It is known that aquaculture may produce negative environmental effects on marine ecosystems. Southern Chile is one of the most important salmon and mussel-producing areas in the world. Here we assess the ecological status of benthic communities near farming centers in Caucahue Channel, Chiloe, which has been used intensely for salmon and mussel production for 30 years. Methods The macrofauna, sediments and water column were characterized at distances of 5 to 100 m from three salmon and three mussel-producing centers. Information was also obtained from reference sites 500 to 3000 m from these aquaculture farms. The macrofauna and environmental conditions during winter were analyzed using uni- and multivariate analysis and the AZTI Marine Biotic Index (AMBI) as an indicator of benthic community condition. Results (i) There is a high degree of spatial dissimilarity in macrofauna and environmental variables among sampling sites and types of environments (far from or near farming centers) and between the northern and southern areas of the channel; (ii) sediment structure (mean grain size and percentage of total organic matter) correlated with the observed dissimilarities in macrofauna communities; and (iii) the level of perturbation according to AMBI was heterogeneous, with sites in the undisturbed/normal range to moderately disturbed/polluted. Conclusions We found a high spatial dissimilarity in benthic macrofauna and environmental variables among sampling sites, environmental types and between the northern and southern areas of the channel. AMBI and multivariate community-environment analysis are useful tools to define the level of perturbation of a geographic area at different spatial scales, using all the ecological information from each sample and replicates.

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Fine-Scale Mapping of Mega-Epibenthic Communities and Their Patch Characteristics on Two New Zealand Seamounts

Frontiers in Marine Science ◽

10.3389/fmars.2021.765407 ◽

2021 ◽

Vol 8 ◽

Author(s):

Savannah L. Goode ◽

Ashley A. Rowden ◽

David A. Bowden ◽

Malcolm R. Clark ◽

Fabrice Stephenson

Keyword(s):

Community Structure ◽

New Zealand ◽

Environmental Variables ◽

Community Dynamics ◽

Spatial Scales ◽

Benthic Communities ◽

Environmental Drivers ◽

Fine Scale ◽

Patch Characteristics ◽

Epibenthic Communities

Seamounts are common features of the deep seafloor that are often associated with aggregations of mega-epibenthic fauna, including deep-sea corals and sponges. Globally, many seamounts also host abundant fish stocks, supporting commercial bottom trawl fisheries that impact non-target benthic species through damage and/or removal of these non-target species. However, the effects of bottom trawling on seamount benthic communities, as well as their recovery potential, will vary over the total seamount area because of differences in within seamount habitat and community structure. It is therefore important to understand fine-scale community dynamics, community patch characteristics, and the environmental drivers contributing to these patterns to improve habitat mapping efforts on seamounts and to determine the potential for benthic communities on seamounts to recover from fishing disturbances. Here we analysed the structure and distribution of mega-epibenthic communities on two New Zealand seamounts with different physical environments to determine which environmental variables best correlated with variation in community structure within each seamount. We used the identified environmental variables to predict the distribution of communities beyond the sampled areas, then described the spatial patterns and patch characteristics of the predicted community distributions. We found the environmental variables that best explained variations in community structure differed between the seamounts and at different spatial scales. These differences were reflected in the distribution models: communities on one seamount were predicted to form bands with depth, while on the other seamount communities varied mostly with broadscale aspect and the presence of small pinnacles. The number and size of community patches, inter-patch distances, and patch connectedness were found to differ both within and between seamounts. These types of analyses and results can be used to inform the spatial management of seamount ecosystems.

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A widespread decrease in productivity of sockeye salmon (Oncorhynchus nerka) populations in western North America

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f2012-063 ◽

2012 ◽

Vol 69 (8) ◽

pp. 1255-1260 ◽

Cited By ~ 75

Author(s):

Randall M. Peterman ◽

Brigitte Dorner

Keyword(s):

Sockeye Salmon ◽

Spatial Scales ◽

Oncorhynchus Nerka ◽

Geographic Area ◽

Fraser River ◽

Western North America ◽

Southeast Alaska ◽

The Past ◽

Large Geographic Area ◽

Marine Areas

We used data on 64 stocks of sockeye salmon ( Oncorhynchus nerka ) from British Columbia (B.C.), Washington, and Alaska to determine whether recent decreases in abundance and productivity observed for Fraser River, B.C., sockeye have occurred more widely. We found that decreasing time trends in productivity have occurred across a large geographic area ranging from Washington, B.C., southeast Alaska, and up through the Yakutat peninsula, Alaska, but not in central and western Alaska. Furthermore, a pattern of predominantly shared trends across southern stocks and opposite trends between them and stocks from western Alaska was present in the past (1950–1985), but correlations have intensified since then. The spatial extent of declining productivity of sockeye salmon has important implications for management as well as research into potential causes of the declines. Further research should focus on mechanisms that operate at large, multiregional spatial scales, and (or) in marine areas where numerous correlated sockeye stocks overlap.

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Multi-scale data on intertidal macrobenthic biodiversity and environmental features in three New Zealand harbours

10.5194/essd-2019-151 ◽

2019 ◽

Author(s):

Casper Kraan ◽

Barry L. Greenfield ◽

Simon F. Thrush

Keyword(s):

New Zealand ◽

Environmental Variables ◽

Spatial Organization ◽

Spatial Scales ◽

Species Distributions ◽

Sediment Grain Size ◽

High Resolution Data ◽

Multi Scale ◽

Grain Size Distributions ◽

Patterns And Processes

Abstract. Understanding how the plants and animals that live in the seafloor vary in their spatial patterns of diversity and abundance is fundamental to gaining insight in the role of biodiversity in maintaining ecosystem functioning in coastal ecosystems, as well as advancing the modelling of species distributions under realistic assumptions. Yet, it is virtually unknown how the relationships between abundance patterns and different biotic and environmental processes change depending on spatial scales, which is mainly due to a lack of data. Within the project Spatial Organization of Species Distributions: Hierarchical and Scale-Dependent Patterns and Processes in Coastal Seascapes at the National Institute for Water and Atmospheric Research (NIWA) in New Zealand we collected multi-scale and high-resolution data on macrobenthic biodiversity. We found 146 species, i.e. bivalves, polychaetes and crustaceans (> 500 μm) that live hidden in marine sandflats, and collected point measurements of important environmental variables (sediment grain-size distributions, chlorophyll a concentration, and visible sandflat parameters) in three large intertidal Harbours (Kaipara, Tauranga and Manukau). In each Harbour we sampled 400 points for macrobenthic community composition and abundances, as well as the full set of environmental variables. Using an elaborate sampling design, we were able to cover scales from 30 centimetres to a maximal extent of 1 km. All data and extensive metadata are available from the data publisher PANGAEA via the persistent identifier https://doi.org/10.1594/PANGAEA.903448.

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Heavy metal pollution and macrobenthic assemblages in soft sediments in two Sydney estuaries, Australia

Marine and Freshwater Research ◽

10.1071/mf97188 ◽

1998 ◽

Vol 49 (6) ◽

pp. 533 ◽

Cited By ~ 57

Author(s):

Jonathan S. Stark

Keyword(s):

Heavy Metals ◽

Environmental Variables ◽

Spatial Scales ◽

Organic Matter Content ◽

Matter Content ◽

Soft Sediments ◽

Lead And Zinc ◽

Macrobenthic Assemblages ◽

Order Of Magnitude ◽

Copper Lead

The influence of heavy metals (copper, lead and zinc) associated with urban runoff, on assemblages of macrofauna in intertidal soft sediments was studied in two estuaries in the Sydney region. The patterns of distribution and abundance of fauna and assemblages was found to vary significantly at several spatial scales: within bays in an estuary, between bays within an estuary and between bays from different estuaries. Significant differences were found in concentrations of heavy metals in sediments, but there was very little difference among bays in other environmental variables: grain-size characteristics and organic matter content of sediments. Bays polluted by heavy metals had significantly different assemblages to unpolluted bays, were generally less diverse and were characterized by an order-of-magnitude greater abundance of capitellids, spionids, nereids and bivalves. Unpolluted bays had greater abundance of crustaceans and several polychaete families, including paraonids and nephtyids and were generally more diverse. There was a significant correlation between patterns of assemblages and concentrations of heavy metals, but not with other environmental variables.

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Consistent patterns of variation in macrobenthic assemblages and environmental variables over multiple spatial scales using taxonomic and functional approaches

Marine Environmental Research ◽

10.1016/j.marenvres.2016.08.011 ◽

2016 ◽

Vol 120 ◽

pp. 191-201 ◽

Cited By ~ 12

Author(s):

Puri Veiga ◽

Ana Catarina Torres ◽

Fernando Aneiros ◽

Isabel Sousa-Pinto ◽

Jesús S. Troncoso ◽

...

Keyword(s):

Environmental Variables ◽

Spatial Scales ◽

Multiple Spatial Scales ◽

Macrobenthic Assemblages

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Landscape Influences on Stream Habitats and Biological Assemblages

Landscape Influences on Stream Habitats and Biological Assemblages ◽

10.47886/9781888569766.ch24 ◽

2006 ◽

Keyword(s):

Land Cover ◽

Ictalurus Punctatus ◽

Environmental Variables ◽

Agricultural Land ◽

Fish Assemblages ◽

Spatial Scales ◽

Species Abundance ◽

Ecological Condition ◽

Basin Scale ◽

Assemblage Metrics

Abstract.—We analyzed data from 38 sites on 31 large rivers in Wisconsin to characterize the influence of environmental variables at the basin, reach, and site scales on fish assemblages. Electrofishing and site habitat data were collected for a distance of 1.6 km per site. Environmental variables included conductivity, substrate, and fish cover at the site scale; distance to impoundments, dams, and length of riverine habitat at the reach scale; and land cover, climate, and geology at the basin scale. Of the 77 fish species found, 39 occurred in more than 10% of the sites and were retained for analyses of fish abundance and biomass. Redundancy analysis (RDA) was used to relate species abundance, biomass, and 16 assemblage metrics to environmental variables at the three spatial scales. The site and basin scales defined fishes along a gradient from high conductivity, fine substrate, and agricultural land cover to low conductivity, rocky substrate, and forested land cover. For abundance and biomass, the strongest assemblage pattern contrasted northern hog sucker Hypentelium nigricans, blackside darter Percina maculata, and logperch P. caprodes with common carp Cyprinus carpio, channel catfish Ictalurus punctatus, and sauger Sander canadensis. The H. nigricans group, along with high values of index of biotic integrity and some assemblage metrics (percent lithophilic spawners, percent round-bodied suckers), corresponded with the forested end of the ecological gradient, whereas the C. carpio group and percent anomalies corresponded with the agricultural end. Natural environmental conditions, including bedrock geology type, bedrock depth, surficial geology texture, basin area, and precipitation, also influenced the fish assemblage. Partial RDA procedures partitioned the explained variation among spatial scales and their interactions. We found that widespread land cover alterations at the basin scale were most strongly related to fish assemblages across our study area. Understanding the influence of environmental variables among multiple spatial scales on fish assemblages can improve our ability to assess the ecological condition of large river systems and subsequently target the appropriate scale for management or restoration efforts.

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Evaluating impacts of bottom trawling and hypoxia on benthic communities at the local, habitat, and regional scale using a modelling approach

ICES Journal of Marine Science ◽

10.1093/icesjms/fsz219 ◽

2019 ◽

Vol 77 (1) ◽

pp. 278-289 ◽

Cited By ~ 1

Author(s):

P D van Denderen ◽

S G Bolam ◽

R Friedland ◽

J G Hiddink ◽

K Norén ◽

...

Keyword(s):

Baltic Sea ◽

Spatial Scales ◽

Benthic Communities ◽

Regional Scale ◽

The Baltic Sea ◽

Benthic Habitats ◽

Bottom Trawling ◽

Management Actions ◽

The Baltic ◽

Local Habitat

Abstract Bottom trawling disturbance and hypoxia are affecting marine benthic habitats worldwide. We present an approach to predict their effects on benthic communities, and use the approach to estimate the state, the biomass relative to carrying capacity, of the Baltic Sea at the local, habitat, and regional scale. Responses to both pressures are expected to depend on the longevity of fauna, which is predicted from benthic data from 1558 locations. We find that communities in low-salinity regions mostly consist of short-lived species, which are, in our model, more resilient than those of the saline areas. The model predicts that in 14% of the Baltic Sea region benthic biomass is reduced by at least 50%, whereas an additional 8% of the region has reductions of 10–50%. The effects of hypoxia occur over larger spatial scales and lead to a low state of especially deep habitats. The approach is based on a simple characterization of the benthic community, which comes with high uncertainty, but allows for the identification of benthic habitats that are at greatest risk and prioritization of management actions at the regional scale. This information supports the development of sustainable approaches to manage impact of human activities on benthic ecosystems.

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Sensing the Same Fishing Fleet with AIS and VIIRS: A Seven-Year Assessment of Squid Jiggers in FAO Major Fishing Area 41

Remote Sensing ◽

10.3390/rs12010032 ◽

2019 ◽

Vol 12 (1) ◽

pp. 32

Author(s):

Javier Ruiz ◽

Isabel Caballero ◽

Gabriel Navarro

Keyword(s):

Infrared Imaging ◽

Spatial Scales ◽

Fishing Effort ◽

Automatic Identification ◽

Identification System ◽

Sources Of Information ◽

Food And Agriculture ◽

Food And Agriculture Organization ◽

High Degree ◽

Fishing Area

Global Fishing Watch and VIIRS-DNB (visible infrared imaging radiometer suite day/night band) signals are compared for the jigger fleet in FAO (Food and Agriculture Organization of the United Nations) Major Fishing Area 41 during the maximum feasible time span (2012–2018). Both signals have shown a high degree of consistency at all temporal and spatial scales analyzed, including seasonal cycles, lack of signal for some years and interannual tendencies. This indicates that both signals are a fair representation of the fishing effort exerted by the jigger fleet in this zone. The high degree of consistency does not support views questioning satellite AIS (automatic identification system) as a reliable tool to survey fishing activities. Instead, our results add evidence supporting the value of remote sensing, in particular, when independent sources of information (such as VIIRS-DNB and AIS) are combined, as a relevant tool to add transparency and support compliance of fishing activities in vast and distant regions of the ocean.

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