Soft sediment ecology of Lough Hyne Marine Reserve - spatial and temporal patterns

Distribution of soft sediment benthic fauna and the environmental factors affecting them were studied, to investigate changes across spatial and temporal scales. Investigations took place at Lough Hyne Marine Reserve using a range of methods. Data on the sedimentation rates of organic and inorganic matter were collected at monthly intervals for one year at a number of sites around the Lough, by use of vertical midwater-column sediment traps. Sedimentation of these two fractions were not coupled; inorganic matter sedimentation depended on hydrodynamic and weather factors, while the organic matter sedimentation was more complex, being dependent on biological and chemical processes in the water column. The effects of regular hypoxic episodes on benthic fauna due to a natural seasonal thermocline were studied in the deep Western Trough, using camera-equipped remotely-operated vehicle to follow transects, on a three-monthly basis over one year. In late summer, the area below the thermocline of the Western Trough was devoid of visible fauna. Decapod crustaceans were the first taxon to make use of ameliorating oxygen conditions in autumn, by darting below the thermocline depth, most likely to scavenge. This was indicated by tracks that they left on the surface of the Trough floor. Some species, most noticeably Fries’ goby Lesueurigobius friesii, migrated below the thermocline depth when conditions were normoxic and established semi-permanent burrows. Their population encompassed all size classes, indicating that this habitat was not limited to juveniles of this territorial species. Recolonisation by macrofauna and burrowing megafauna was studied during normoxic conditions, from November 2009 to May 2010. Macrofauna displayed a typical post-disturbance pattern of recolonisation with one species, the polychaete Scalibregma inflatum, occurring at high abundance levels in March 2010. In May, this population had become significantly reduced and a more diverse community was established. The abundance of burrowing infauna comprising decapods crabs and Fries’ gobies, was estimated by identifying and counting their distinctive burrow structures. While above the summer thermocline depth, burrow abundance increased in a linear fashion, below the thermocline depth a slight reduction of burrow abundance occurred in May, when oxygen conditions deteriorated again. The majority of the burrows occurring in May were made by Fries’ gobies, which are thought to encounter low oxygen concentrations in their burrows. Reduction in burrow abundance of burrowing shrimps Calocaris macandreae and Callianassa subterranea (based on descriptions of burrow structures from the literature), from March to May, might be related to their reduced activity in hypoxia, leading to loss of structural burrow maintenance. Spatial and temporal changes to macrofaunal assemblage structures were studied seasonally for one year across 5 sites in the Lough and subject to multivariate statistical analysis. Assemblage structures were significantly correlated with organic matter levels in the sediment, the amounts of organic matter settling out of the water column one month before macrofaunal sampling took place as well as current speed and temperature. This study was the first to investigate patterns and processes in the Lough soft sediment ecology across all 3 basins on a temporal and spatial scale. An investigation into the oceanographic aspects of the development, behaviour and break-down of the summer thermocline of Lough Hyne was performed in collaboration with researchers from other Irish institutions

Comparison of Inorganic and Organic Matter Sedimentation in a Natural Laboratory: A One-Year Study at Lough Hyne Marine Reserve, Ireland

Measuring sedimentation rates may provide useful information on the habitat preferences of marine organisms. To understand the effect of flow rates and meteorological conditions on sedimentation in the absence of other confounding factors, sedimentation of organic (OM) and inorganic (IOM) matters was measured at 6 sites in Lough Hyne Marine Reserve (a semienclosed marine lake) over the course of 13 months. During winter, both OM and IOM were imported to the Lough, peaking in December at Whirlpool, the site nearest to the Lough entrance, likely as a result of extreme weather conditions causing resuspension of matter outside the Lough. Highest inorganic matter (IOM) sedimentation occurred in December (47.36 gm−2d−1 at Whirlpool Cliff) and was related to November wind speeds (, ). Decreasing current speed also caused a decline in IOM sedimentation. Highest OM sedimentation occurred in December at Whirlpool (5.59 gm−2d−1), but was not related to meteorological conditions. No single environmental factor strongly influenced organic matter (OM) sedimentation. One-way ANOVAs on OM and log-transformed IOM data showed that sedimentation differed significantly amongst the six sites within the Lough. Increased plankton production in the Lough during summer led to increased OM sedimentation in areas of low current speed away from the entrance of the Lough

Assessing costs and benefits of measures to achieve good environmental status in European regional seas: challenges, opportunities, and lessons learnt

The EU Marine Strategy Framework Directive (MSFD) requires Member States to assess the costs and benefits of Programmes of Measures (PoMs) put in place to ensure that European marine waters achieve Good Environmental Status by 2020. An interdisciplinary approach is needed to carry out such an assessment whereby economic analysis is used to evaluate the outputs from ecological analysis that determines the expected effects of such management measures. This paper applies and tests an existing six-step approach to assess costs and benefits of management measures with potential to support the overall goal of the MSFD and discusses a range of ecological and economic analytical tools applicable to this task. Environmental cost-benefit analyses are considered for selected PoMs in three European case studies: Baltic Sea (Finland), East Coast Marine Plan area (UK), and the Bay of Biscay (Spain). These contrasting case studies are used to investigate the application of environmental cost-benefit analysis (CBA) including the challenges, opportunities and lessons learnt from using this approach. This paper demonstrates that there are opportunities in applying the six-step environmental CBA framework presented to assess the impact of PoMs. However, given demonstrated limitations of knowledge and data availability, application of other economic techniques should also be considered (although not applied here) to complement the more formal environmental CBA approach

Bioremediation of waste under ocean acidification: Reviewing the role of Mytilus edulis

Waste bioremediation is a key regulating ecosystem service, removing wastes from ecosystems through storage, burial and recycling. The bivalve Mytilus edulis is an important contributor to this service, and is used in managing eutrophic waters. Studies show that they are affected by changes in pH due to ocean acidification, reducing their growth. This is forecasted to lead to reductions in M. edulis biomass of up to 50% by 2100. Growth reduction will negatively affect the filtering capacity of each individual, potentially leading to a decrease in bioremediation of waste. This paper critically reviews the current state of knowledge of bioremediation of waste carried out by M. edulis, and the current knowledge of the resultant effect of ocean acidification on this key service. We show that the effects of ocean acidification on waste bioremediation could be a major issue and pave the way for empirical studies of the topic

Cloud-native Remotely-sensed Seagrass Mapping and Blue Carbon Estimation in Mozambique

The interest in the blue carbon sequestration has been increasing in the past few years due to their potential in climate change. Despite only covering less than 0.2% of the global seafloor, seagrass meadows store 10% of the world’s atmospheric carbon deep in the soils. The extent of seagrass meadows has been declining at an alarming rate of 1.5%/year on average. Field data collection of the underwater habitats can be costly due to the environmental challenges. Our goal in the Biodiversity of the Coastal Ocean: Monitoring with Earth Observation (BiCOME) project is to develop analysis-ready products that can be used for Essential Biodiversity Variable (EBV) quantification and downstream impact. In this study, we mapped the seagrass extent and stored blue carbon across the entire Mozambican coastlines. We processed 9,089 multi-temporal Sentinel-2 image tiles across 34,193km2 of the coastal area in Mozambique and mapped the satellite derived bathymetry (SDB) and seagrass extent by using in-situ bathymetry data, and both in-situ and self-annotated habitat data. The seagrass extent was mapped with the Random Forest image classification, resulting in 1,779.3 km2 of seagrass meadows, located between depths of 1.6 and 9.2 m. We estimated the seagrass blue carbon stocks by multiplying the mapped nationwide seagrass extent with their corresponding Tier 1 and Tier 2 carbon stock estimates. Based on our Tier 1 carbon stock assessment, the national seagrass blue carbon stock was estimated at 1.78-147 million Mg and our Tier 2 carbon stock assessment results in 1.64-4.35 million Mg

Assessment of a contemporary Earth System Science approach and Essential Biodiversity Variables for subtidal seagrasses in Mozambique

The interest in the blue carbon sequestration provided by seagrasses, mangroves and tidal flats has been increasing in the past few years due to the potential of these nature-based solutions in climate change mitigation within a conservation and restoration context. Despite only covering less than 0.2% of the global seafloor, seagrass meadows store 10% of the world’s atmospheric carbon deep in the soils. The extent of seagrass meadows has been declining at an alarming rate of 1.5%/year on average. Field data collection of the underwater habitats can be costly due to the environmental challenges. Our goal in the Biodiversity of the Coastal Ocean: Monitoring with Earth Observation (BiCOME) project is to develop analysis-ready products that can be used for Essential Biodiversity Variable (EBV) quantification and downstream impact. This study highlights our efforts in mapping the seagrass extent and stored blue carbon across the entire Mozambican coastlines. We processed 9,089 100x100km2 Sentinel-2 image tiles across 34,193km2 of the coastal area in Mozambique acquired between 14 December 2018 and 20 April 2020 with our multitemporal processor to produce an image synthesis with minimized effects from the environmental noises such as waves, sunglint, cloud cover, and turbidity. By using in-situ bathymetry data, and both in-situ and self-annotated habitat data, we mapped the full extent of bathymetry and seagrass habitats in the optically shallow water areas of Mozambique. We mapped the bathymetry using the Clustering-based Lyzenga method, which helps detect the depth at which the seagrass meadows are located. The seagrass extent was mapped by employing the Random Forest machine learning image classification, resulting in 1,779.3 km2 of seagrass meadows, which covers 2.7% of the study area, located between depths of 1.6 and 9.2 m. We estimated the seagrass blue carbon stocks by multiplying the mapped nationwide seagrass extent with their corresponding Tier 1 and Tier 2 carbon stock estimates. Based on our Tier 1 carbon stock assessment, the national seagrass blue carbon stock was estimated at 1.78-147 million Mg and our Tier 2 carbon stock assessment results in 1.64-4.35 million Mg, which highlights a large overestimation of the Tier 1 globally averaged assessment. These analysis-ready products we developed with multidisciplinary methodologies (extent, bathymetry, and carbon stock processors) can be further used to design and develop relevant EBVs for subtidal seagrass meadows. Moreover, the estimated seagrass habitat map can be useful to highlight the importance of seagrass restoration and conservation which can promote more cost-effective and targeted action for coastal biodiversity and blue carbon ecosystem services of seagrasses in tropical regions worldwide

Ecosystem indicators to measure the effectiveness of marine nature-based solutions on society and biodiversity under climate change

An assessment framework of marine ecosystem services (ES) indicators to quantify the socio-ecological effectiveness of nature-based solutions (NBS) and nature-inclusive harvesting (NIH) under climate-driven changes was developed. It creates a common understanding about the health status of ecosystems, their services (ES), and the impact of implementing NBS&NIH to inform policymakers and the public. The two NBS considered were restoration and conservation which need to be performed considering the sustainable harvesting of marine resources (NIH). The interaction between the biodiversity indicators with the socioeconomic, response and pressure indicators was established using the ES cascade. However, it was also linked to other environmental (e.g., DAPSI(W)R(M)) and economic frameworks such as the Standard National Account (SNA) and the System of Environment Economic Accounting (SEEA). A set of 155 multidisciplinary indicators were identified through a literature review and their effectiveness in measuring ES under changing climate. Biodiversity & environmental as well as Pressure indicators are the most numerous in the list representing 34 % and 23 % of the total respectively, while only 12 % of the used Indicators below to the economic dimension. Socioeconomic indicators considering CC are rarely contemplated, except for a short list redefining output and demand approach indicators to aggregate a carbon footprint valuation. For cultural services economic indicators dominate, whereas sparse for provisioning and regulating. The 70 % of the selected indicators were also empirically verified with 27 European storylines. Storylines have high coverage of biodiversity, environmental indicators, and CC indicators (91 %), lower coverage of economic (71 %) and poorer related to social (31 %) indicators. Harvest, pressure and/or habitats are clearly the groups of indicators majority used when evaluating the ES on marine and coastal ecosystems both in terms of the number of used indicators but also, the frequency of use. Despite the increase of ES research, this study identifies 14 substantial gaps or weaknesses limiting the guidance for NBS&NIH implementation derived from the employment of an unbalanced (between dimensions and key groups) number of quantitative indicators

Biodiversity from Remote Sensing of Coastal Areas for Science and Societal Applications: User Requirements Synthesis and Preliminary Results

The Convention on Biological Diversity and the UN Decade of the Ocean have set targets to reaching ocean sustainability by 2050. To assess if these targets have been met, each target is linked to a set of indicators measuring Essential Biodiversity Variables (EBV). Marine and coastal habitats are under threat through numerous anthropogenic stressors. At the same time, measuring indicators in the marine and coastal environment is costly, time consuming and unreliable due to weather conditions leading to a dearth of data in these areas. Satellite remote sensing is proposed as a tool to complement in-situ observations. It can measure some EBVs in a more consistent and reliable manner and increase the area covered as well as spatial and temporal resolution. However, due to the need for specific training and infrastructure to analyse raw remote sensing data, there is a need to understand the end users’ requirements to use such data for biodiversity monitoring. The European Space Agency funded Bi-COME project (Biodiversity of the Coastal Ocean: Monitoring with Earth Observation) aims to develop products that help measuring more EBVs more effectively and to involve stakeholders in the development process. To this end, we are collecting the user requirements of seven case study partners using semi-structured interviews. We aim to compare their current approaches with new Earth Observation products by learning about their current methods to measure EBVs, ask what they would like to achieve by the use of improved Earth Observation products and how they are able to access such data. The case study partners consist of managers and data providers to local environmental managers of intertidal, subtidal and pelagic marine habitats. The case study sites consist of sandy intertidal habitat in France, seagrass habitats in Mozambique and pelagic floating vegetation in India and the Caribbean Sea. We plan to interview the case study partners after they have tested the products created so that they can help shape the development according to their needs. This presentation will discuss results from the first set of interviews