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Author(s):  
Rob Critchlow ◽  
Charles A. Cunningham ◽  
Humphrey Q. P. Crick ◽  
Nicholas A. Macgregor ◽  
Michael D. Morecroft ◽  
...  

AbstractProtected area (PA) networks have in the past been constructed to include all major habitats, but have often been developed through consideration of only a few indicator taxa or across restricted areas, and rarely account for global climate change. Systematic conservation planning (SCP) aims to improve the efficiency of biodiversity conservation, particularly when addressing internationally agreed protection targets. We apply SCP in Great Britain (GB) using the widest taxonomic coverage to date (4,447 species), compare spatial prioritisation results across 18 taxa and use projected future (2080) distributions to assess the potential impact of climate change on PA network effectiveness. Priority conservation areas were similar among multiple taxa, despite considerable differences in spatial species richness patterns; thus systematic prioritisations based on indicator taxa for which data are widely available are still useful for conservation planning. We found that increasing the number of protected hectads by 2% (to reach the 2020 17% Aichi target) could have a disproportionate positive effect on species protected, with an increase of up to 17% for some taxa. The PA network in GB currently under-represents priority species but, if the potential future distributions under climate change are realised, the proportion of species distributions protected by the current PA network may increase, because many PAs are in northern and higher altitude areas. Optimal locations for new PAs are particularly concentrated in southern and upland areas of GB. This application of SCP shows how a small addition to an existing PA network could have disproportionate benefits for species conservation.


2022 ◽  
Vol 174 ◽  
pp. 113229
Author(s):  
Megan Andrew-Priestley ◽  
Katie Newton ◽  
Margaret E. Platell ◽  
Lisa Le Strange ◽  
Harry Houridis ◽  
...  

2021 ◽  
Author(s):  
◽  
Cong Zeng

<p>Knowledge about and understanding of population structure and connectivity of deep-sea fauna decreases with increasing depth, but such information is crucial for the management of vulnerable marine ecosystems (VMEs) in particular. As such, research using genetic markers, which does not require knowledge of ecological or environmental processes as a prerequisite for the analysis, is a practical method to investigate population connectivity of VME indicator taxa. However, population genetics studies are yet to be broadly conducted in the deep sea around New Zealand.  To provide background information and develop hypothesises for this research, 196 population genetic studies of deep-sea fauna were reviewed and analysed. Based on the collected studies, four different patterns of spatial genetic structure were observed: global homogeneous, oceanic, regional, and fine structure. These different structures were reported that they were related to depth, topography, distance between populations, temperature and other biological factors. Quantification of the relationship between these factors and the detection of barriers to gene flow (barrier detection) showed that depth, currents and topography contributed significantly to barrier detection and depth and topography were acting as a barrier to gene flow in the deep sea. Furthermore, different sampling strategies and different genetic marker types significantly influenced genetic barrier detection. Comparison amongst different habitats suggested that different conservation strategies should be developed for different habitat types (Chapter 2).  This study used different genetic markers to assess the genetic connectivity amongst VME indicator taxa Vulnerable Marine Ecosystems (VME). Seven VME indicator taxa were selected: 4 sponges (Neoaulaxinia persicum, Penares sp., Pleroma menoui and Poecillastra laminaris) and 3 corals (Goniocorella dumosa, Madrepora oculata and Solenosmilia variabilis), at different spatial scales. Due to lack of genetic information for these species, genetic markers were developed for Poecillastra laminaris (0) and S. variabilis (Chapter 4).  A geographic province (northern-southern province), region (north-central-south), and geomorphic feature hierarchical testing framework was employed to examine species-specific genetic variation in mitochondrial (COI, Cytb and 12S) and nuclear markers (microsatellites) amongst populations of four deep-sea sponges within the New Zealand region. For Poecillastra laminaris, significant mitochondrial and nuclear DNA genetic differences were revealed amongst biogeographic provinces. In contrast, no significant structure was detected across the same area for Penares sp. Both Neoaulaxinia persicum and Pleroma menoui were only available from the northern province, in which Pleroma menoui showed no evidence of genetic structure, but N. persicum exhibited a geographic differentiation in 12S. No depthrelated isolation was observed for any of the four species at the mitochondrial markers, nor at the microsatellite loci for Poecillastra laminaris. Genetic connectivity in Poecillastra laminaris is likely to be influenced by oceanic sub-surface currents that generate routes for gene flow and may also act as barriers to dispersal. Although data are limited, these results suggest that the differences in patterns of genetic structure amongst the species can be attributed to differences in life history and reproductive strategies. The results are discussed in the context of existing marine protected areas, and the future design of spatial management measures for protecting VMEs in the New Zealand region (Chapter 5).  To better understand the vulnerability of stony corals (Goniocorella dumosa, Madrepora oculata and Solenosmilia variabilis) to disturbance within the New Zealand region, and to guide marine protected area design, genetic structure and connectivity were determined using microsatellite loci and DNA sequencing. Analyses compared population genetic differentiation between two biogeographic provinces, amongst three sub-regions (north-central-south), and amongst geomorphic features. Population genetic differentiation varied amongst species and between marker types. For G. dumosa, genetic differentiation existed amongst regions and populations on geomorphic features, but not between provinces. For M. oculata, only a north-central-south regional structure was observed. For S. variabilis, genetic differentiation was observed between provinces, amongst regions and amongst geomorphic features based on microsatellite variation. Multivariate analyses indicated that populations on the Kermadec Ridge were genetically different from Chatham Rise populations in all three coral species. Furthermore, a significant isolation-by-depth pattern was observed for both marker types in G. dumosa, and also in ITS of M. oculata. An isolation-by-distance pattern was found in microsatellites of S. variabilis. Migrate analysis showed that medium to high self-recruitment were detected in all geomorphic feature populations, and different species presented different genetic connectivity patterns. These different patterns of population genetic structure and connectivity at a range of spatial scales indicate that flexible spatial management is required for the conservation of deep-sea corals around New Zealand (Chapter 6).  Understanding the deep-sea ecological processes that shape spatial genetic patterns of species is critical for predicting evolutionary dynamics and defining significant evolutionary and/or management units. In this study, the potential role of environmental factors in shaping the genetic structure of the 7 deep-sea habit-providing study species was investigated using a seascape genetics approach. The genetic data were acquired from nuclear and mitochondrial sequences and microsatellite genotype data, and 25 environmental variables (5 topographic, 17 physiochemical and 3 biological variables). The results indicated that environmental factors affected genetic variation differently amongst the species. However, factors related to current and food source explained the north-central-south genetic structure in sponges and corals, and environmental variation in these parameters may be acting as a barrier to gene flow. At the geomorphic feature level, the DistLM and dbRDA analysis showed that factors related to the food source and topography were most related to genetic variation in microsatellites of sponge and corals. This study highlights the utility of seascape genetic studies to better understand the processes shaping the genetic structure of organisms (Chapter 7).  The outcomes of this study provide vital information to assist in effective management and conservation of VME indicator taxa and contribute to an understanding of evolutionary and ecological processes in the deep sea (Chapter 8).</p>


2021 ◽  
Author(s):  
◽  
Cong Zeng

<p>Knowledge about and understanding of population structure and connectivity of deep-sea fauna decreases with increasing depth, but such information is crucial for the management of vulnerable marine ecosystems (VMEs) in particular. As such, research using genetic markers, which does not require knowledge of ecological or environmental processes as a prerequisite for the analysis, is a practical method to investigate population connectivity of VME indicator taxa. However, population genetics studies are yet to be broadly conducted in the deep sea around New Zealand.  To provide background information and develop hypothesises for this research, 196 population genetic studies of deep-sea fauna were reviewed and analysed. Based on the collected studies, four different patterns of spatial genetic structure were observed: global homogeneous, oceanic, regional, and fine structure. These different structures were reported that they were related to depth, topography, distance between populations, temperature and other biological factors. Quantification of the relationship between these factors and the detection of barriers to gene flow (barrier detection) showed that depth, currents and topography contributed significantly to barrier detection and depth and topography were acting as a barrier to gene flow in the deep sea. Furthermore, different sampling strategies and different genetic marker types significantly influenced genetic barrier detection. Comparison amongst different habitats suggested that different conservation strategies should be developed for different habitat types (Chapter 2).  This study used different genetic markers to assess the genetic connectivity amongst VME indicator taxa Vulnerable Marine Ecosystems (VME). Seven VME indicator taxa were selected: 4 sponges (Neoaulaxinia persicum, Penares sp., Pleroma menoui and Poecillastra laminaris) and 3 corals (Goniocorella dumosa, Madrepora oculata and Solenosmilia variabilis), at different spatial scales. Due to lack of genetic information for these species, genetic markers were developed for Poecillastra laminaris (0) and S. variabilis (Chapter 4).  A geographic province (northern-southern province), region (north-central-south), and geomorphic feature hierarchical testing framework was employed to examine species-specific genetic variation in mitochondrial (COI, Cytb and 12S) and nuclear markers (microsatellites) amongst populations of four deep-sea sponges within the New Zealand region. For Poecillastra laminaris, significant mitochondrial and nuclear DNA genetic differences were revealed amongst biogeographic provinces. In contrast, no significant structure was detected across the same area for Penares sp. Both Neoaulaxinia persicum and Pleroma menoui were only available from the northern province, in which Pleroma menoui showed no evidence of genetic structure, but N. persicum exhibited a geographic differentiation in 12S. No depthrelated isolation was observed for any of the four species at the mitochondrial markers, nor at the microsatellite loci for Poecillastra laminaris. Genetic connectivity in Poecillastra laminaris is likely to be influenced by oceanic sub-surface currents that generate routes for gene flow and may also act as barriers to dispersal. Although data are limited, these results suggest that the differences in patterns of genetic structure amongst the species can be attributed to differences in life history and reproductive strategies. The results are discussed in the context of existing marine protected areas, and the future design of spatial management measures for protecting VMEs in the New Zealand region (Chapter 5).  To better understand the vulnerability of stony corals (Goniocorella dumosa, Madrepora oculata and Solenosmilia variabilis) to disturbance within the New Zealand region, and to guide marine protected area design, genetic structure and connectivity were determined using microsatellite loci and DNA sequencing. Analyses compared population genetic differentiation between two biogeographic provinces, amongst three sub-regions (north-central-south), and amongst geomorphic features. Population genetic differentiation varied amongst species and between marker types. For G. dumosa, genetic differentiation existed amongst regions and populations on geomorphic features, but not between provinces. For M. oculata, only a north-central-south regional structure was observed. For S. variabilis, genetic differentiation was observed between provinces, amongst regions and amongst geomorphic features based on microsatellite variation. Multivariate analyses indicated that populations on the Kermadec Ridge were genetically different from Chatham Rise populations in all three coral species. Furthermore, a significant isolation-by-depth pattern was observed for both marker types in G. dumosa, and also in ITS of M. oculata. An isolation-by-distance pattern was found in microsatellites of S. variabilis. Migrate analysis showed that medium to high self-recruitment were detected in all geomorphic feature populations, and different species presented different genetic connectivity patterns. These different patterns of population genetic structure and connectivity at a range of spatial scales indicate that flexible spatial management is required for the conservation of deep-sea corals around New Zealand (Chapter 6).  Understanding the deep-sea ecological processes that shape spatial genetic patterns of species is critical for predicting evolutionary dynamics and defining significant evolutionary and/or management units. In this study, the potential role of environmental factors in shaping the genetic structure of the 7 deep-sea habit-providing study species was investigated using a seascape genetics approach. The genetic data were acquired from nuclear and mitochondrial sequences and microsatellite genotype data, and 25 environmental variables (5 topographic, 17 physiochemical and 3 biological variables). The results indicated that environmental factors affected genetic variation differently amongst the species. However, factors related to current and food source explained the north-central-south genetic structure in sponges and corals, and environmental variation in these parameters may be acting as a barrier to gene flow. At the geomorphic feature level, the DistLM and dbRDA analysis showed that factors related to the food source and topography were most related to genetic variation in microsatellites of sponge and corals. This study highlights the utility of seascape genetic studies to better understand the processes shaping the genetic structure of organisms (Chapter 7).  The outcomes of this study provide vital information to assist in effective management and conservation of VME indicator taxa and contribute to an understanding of evolutionary and ecological processes in the deep sea (Chapter 8).</p>


2021 ◽  
Vol 25 (4) ◽  
pp. 511-521
Author(s):  
F.O. Amiewalan ◽  
F.O. Balogun

Palynological studies was carried out on GZ-1 well from the onshore western Niger Delta in order to recognized a new detected developments in the varieties of key pollen and spore taxa that have shorter and more distinguished interval zones to advance stratigraphical delineation. Palynological analysis was carried out using the conventional maceration technique for recovering acid insoluble organic-walled microfossils from sediments. The result yielded rich and diversified palynomorphs. The main assemblage were dominated by angiosperm pollen grain (dominant global flora from Late Cretaceous onwards) followed by pteridophytes/bryophyte spore. Dinoflagellate cysts, on the contrast, were less diverse while the Gymnosperm pollen were scarce. The identified palynomorph were used to establish seven main zones - AF1 Psilatricolporites crassus zone, AF2 Verrucatosporites usmensis zone, AF3 Triplochiton scleroxylon zone, AF4 Crassoretitriletes vanraadshooveni zone, AF5 Acrostichum aureum zone, AF6 Gemmatriporites ogwashiensis zone and AF7 Retitricolporites irregularis zone in this study. Established on quantitative events, the zones were also divided into seven subzones with some having finer subdivisions into (a) and (b) ranging in age from Early Oligocene to Early Miocene. Previous unfiled event trends of important indicator taxa of spores and pollen accredited to Pelliceria, Caesalapinoideae, Stenochlaena palustris, Polypodiaceae, Lygodium microphyllum, Polypodiaceae, Adiantaceae and Amanoa (Euphorbiaceae) have assisted improvement of formerly used palynological zonation schemes in the Niger Delta. It is anticipated that this quantitative zonation scheme erected, will help with imminent palynostratigraphical studies in the onshore Niger delta area.


2021 ◽  
Vol 8 ◽  
Author(s):  
Laurie Isabel ◽  
David Beauchesne ◽  
Chris McKindsey ◽  
Philippe Archambault

The estuary and the Gulf of St. Lawrence (EGSL), eastern Canada form a vast inland sea that is subjected to numerous anthropogenic pressures. Management tools are needed to detect and quantify their effect on benthic communities. The aims of this study are to analyze the spatial distribution of epibenthic communities in the EGSL and quantify the impact of important pressures on them to identify indicator taxa. Epibenthic communities were sampled at 1314 EGSL sites between 2011 and 2018 by bottom trawling. Cluster analyses revealed the presence of six distinct epibenthic communities that seem to be strongly influenced by oxygen concentration. Threshold analyses confirm that oxygen is an important predictor of epibenthic community composition and distribution. A major oxygen threshold is observed around 50–100 μmol O2 L–1, resulting in a shift of community type. At these concentrations and below, opportunistic taxa dominate the community while sensitive taxa are absent or present at very low abundance. Biomass of the latter only starts to increase when oxygen concentrations reach 150 μmol O2 L–1. The species Actinostola callosa, Actinauge cristata, Ctenodiscus crispatus, and Brisaster fragilis were identified as good indicators for detecting this impact threshold forepibenthic communities. This study provides threshold-based indicator species that help to establish and monitor the ecological state of epibenthic communities in a marine ecosystem exposed to multiple pressures.


2021 ◽  
Vol 8 ◽  
Author(s):  
Susanne J. Lockhart ◽  
John Hocevar

In order to achieve conservation objectives and preserve the biodiversity of the Southern Ocean, a variety of ecosystems must be protected. This holds especially true for the benthic communities of this region that are characteristically mosaic in their spatial distributions. As such, disparate communities cannot be comprehensively assessed by a single blanket methodology. Herein, evidence appropriate to the diverse characteristics of the communities encountered during a submarine expedition demonstrates the particular vulnerability of four sites that exemplify VMEs as defined by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) and the UN’s Fisheries and Agriculture Organization (FAO). Three sites are identified as VMEs based on highly significant abundances of indicator taxa. A fourth is identified based on a high density of cold-water coral taxa, many of which were not observed in abundance at the sites that were triggered as vulnerable by a significantly high abundance of all indicator taxa. The VME at this latter site was richly diverse in coral taxa, many of which are considered particularly vulnerable to climate change, as well as critical for their potential for genuine blue carbon sequestration. As of November, 2018, all four sites are now registered with CCAMLR as VMEs and thus, are afforded protection from all bottom fishing activities. However, if consideration isn’t given to the composition and/or diversity of VME indicator taxa present, in addition to overall abundance/density, some of the most vulnerable communities are left at risk. A blanket threshold for all VME taxa adhered to in fisheries management of the Southern Ocean, and other high seas areas, is grossly insufficient. Without taking a more precautionary approach to identifying and protecting VMEs, CCAMLR will not be able to meet its conservation objectives and may even be putting Antarctic fisheries at risk.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257510
Author(s):  
Jeanine Brantschen ◽  
Rosetta C. Blackman ◽  
Jean-Claude Walser ◽  
Florian Altermatt

Anthropogenic activities are changing the state of ecosystems worldwide, affecting community composition and often resulting in loss of biodiversity. Rivers are among the most impacted ecosystems. Recording their current state with regular biomonitoring is important to assess the future trajectory of biodiversity. Traditional monitoring methods for ecological assessments are costly and time-intensive. Here, we compared monitoring of macroinvertebrates based on environmental DNA (eDNA) sampling with monitoring based on traditional kick-net sampling to assess biodiversity patterns at 92 river sites covering all major Swiss river catchments. From the kick-net community data, a biotic index (IBCH) based on 145 indicator taxa had been established. The index was matched by the taxonomically annotated eDNA data by using a machine learning approach. Our comparison of diversity patterns only uses the zero-radius Operational Taxonomic Units assigned to the indicator taxa. Overall, we found a strong congruence between both methods for the assessment of the total indicator community composition (gamma diversity). However, when assessing biodiversity at the site level (alpha diversity), the methods were less consistent and gave complementary data on composition. Specifically, environmental DNA retrieved significantly fewer indicator taxa per site than the kick-net approach. Importantly, however, the subsequent ecological classification of rivers based on the detected indicators resulted in similar biotic index scores for the kick-net and the eDNA data that was classified using a random forest approach. The majority of the predictions (72%) from the random forest classification resulted in the same river status categories as the kick-net approach. Thus, environmental DNA validly detected indicator communities and, combined with machine learning, provided reliable classifications of the ecological state of rivers. Overall, while environmental DNA gives complementary data on the macroinvertebrate community composition compared to the kick-net approach, the subsequently calculated indices for the ecological classification of river sites are nevertheless directly comparable and consistent.


2021 ◽  
Author(s):  
Steven Anderson ◽  
Emily Ury ◽  
Paul Taillie ◽  
Eric Ungberg ◽  
Christopher Moorman ◽  
...  

Abstract The effects of sea level rise and coastal saltwater intrusion on wetland plants can extend well above the high-tide line due to drought, hurricanes, and groundwater intrusion. Research has examined how coastal salt marsh plant communities respond to increased flooding and salinity, but more inland coastal systems have received less attention. The aim of this study was to identify whether ground layer plants exhibit threshold responses to salinity exposure. We used two vegetation surveys throughout the Albemarle-Pamlico Peninsula (APP) of North Carolina, USA to assess vegetation in a low elevation landscape (< 3.8 m) experiencing high rates of sea level rise (3-4 mm/year). We examined the primary drivers of community composition change using Non-metric Multidimensional Scaling (NMDS), and used Threshold Indicator Taxa Analysis (TITAN) to detect thresholds of compositional change based on indicator taxa, in response to potential indicators of exposure to saltwater (elevation, Na, and the S Ca + Mg). Salinity and elevation explained 64% of the variation in community composition, and we found two salinity thresholds for both soil Na+ (265 and 3843 g Na+/g), and Ca+ + Mg+ (42 and 126 µeq/g ) where major changes in community composition occur on the APP. Similar sets of species showed sensitivity to these different metrics of salt exposure. Overall, our results showed that ground layer plants can be used as reliable indicators of salinity thresholds in coastal wetlands. These results can be used for monitoring salt exposure of ecosystems and for identifying areas at risk for undergoing future community shifts.


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