Differential gene expression and chemical patterns of an intertidal crab inhabiting a polluted port and an adjacent marine protected area

The Impacts of the Multispecies Approach to Caffeine on Marine Invertebrates

Caffeine is one of the most consumed substances by humans through foodstuffs (coffee, tea, drugs, etc.). Its human consumption releases a high quantity of caffeine into the hydrological network. Thus, caffeine is now considered an emergent pollutant sometimes found at high concentrations in oceans and seas. Surprisingly, little research has been conducted on the molecular responses induced by caffeine in marine organisms. We studied, in laboratory conditions, six phylogenetically distant species that perform distinct ecological functions (Actinia equina and Aulactinia verrucosa (cnidarians, predator), Littorina littorea (gastropod, grazer), Magallana gigas (bivalve, filter-feeder), and Carcinus maenas and Pachygrapsus marmoratus (crabs, predator and scavenger)) subjected to caffeine exposure. The antioxidant responses (catalase, CAT; glutathione peroxidase, GPx; superoxide dismutase, SOD), lipid peroxidation (MDA), and the acetylcholinesterase (AChE) activity were estimated when the organisms were exposed to environmental caffeine concentrations (5 μg/L (low), 10 μg/L (high)) over 14 days. Differential levels of responses and caffeine effects were noted in the marine invertebrates, probably in relation to their capacity to metabolization the pollutant. Surprisingly, the filter feeder (M. gigas, oyster) did not show enzymatic responses or lipid peroxidation for the two caffeine concentrations tested. The marine gastropod (grazer) appeared to be more impacted by caffeine, with an increase in activities for all antioxidative enzymes (CAT, GPx, SOD). In parallel, the two cnidarians and two crabs were less affected by the caffeine contaminations. However, caffeine was revealed as a neurotoxic agent to all species studied, inducing high inhibition of AChE activity. This study provides new insights into the sublethal impacts of caffeine at environmentally relevant concentrations in marine invertebrates.

Harnessing the omics revolution to address the global biodiversity crisis

Human disturbances are altering global biodiversity in unprecedented ways. We identify three fundamental challenges underpinning our understanding of global biodiversity (namely discovery, loss, and preservation), and discuss how the omics revolution (e.g. genomics, transcriptomics, proteomics, metabolomics, and meta-omics) can help address these challenges. We also discuss how omics tools can illuminate the major drivers of biodiversity loss, including invasive species, pollution, urbanization, overexploitation, and climate change, with a special focus on highly diverse tropical environments. Although omics tools are transforming the traditional toolkit of biodiversity research, their application to addressing the current biodiversity crisis remains limited and may not suffice to offset current rates of biodiversity loss. Despite technical and logistical challenges, omics tools need to be fully integrated into global biodiversity research, and better strategies are needed to improve their translation into biodiversity policy and practice. It is also important to recognize that although the omics revolution can be considered the biologist's dream, socioeconomic disparity limits their application in biodiversity research.

Comparison of polycyclic aromatic hydrocarbon accumulation in crab tissues with the ambient marine particles from shallow hydrothermal vents, northeast Taiwan

This study investigated and compared polycyclic aromatic hydrocarbons (PAHs) in crab (Xenograpsus testudinatus), suspended particulate matter, and surface sediment sampled from Kuei-shan-tao (KST) shallow water vents just offshore northeast Taiwan. The total concentrations of PAHs (t-PAHs) in suspended particles near the vents (533-685 ng g^-1 dw) were two orders of magnitude higher than the overlying sediment (3.42-6.06 ng g^-1 dw). The t-PAHs in sediment were significantly lower than those found in suspended particulate matter and all crab tissues tested, including hepatopancreas (192-1154 ng g^-1 dw), gill (221-748 ng g^-1 dw), muscle (30-174 ng g^-1 dw), and exoskeleton (22-96 ng g^-1 dw). Principal component analysis (PCA) indicated tissue-specific bioaccumulation of PAHs in crabs. The compositions of PAHs in gill, muscle, and exoskeleton were mainly low molecular weight, while the composition in the hepatopancreas included both high and low molecular weight PAHs. Highly variable but characteristic PAH congeners and concentrations in crab tissues and ambient aquatic particles reflect bioaccumulation.

A multidisciplinary integrated approach using Pachygrapsus marmoratus to assess the impact of port activities on mediterranean marine protected areas

The establishment of marine protected areas is considered the main global strategy to halt the loss of marine biodiversity. Since most of marine areas are open systems, this form of habitat protection cannot prevent their contamination due to human activities performed outside of their borders. Innovative approaches to assess the health status of protected marine habitats are therefore needed. Here we developed a multidisciplinary approach that combines ecological characteristics, bioaccumulation of inorganic and organic pollutants, cell damage (micronuclei frequency, nuclear alterations and LPO) and enzymatic (AChE, CAT, IDH, LDH, GST and CAT) markers focused on an intertidal brachyuran crab, Pachygrapsus marmoratus, to assess the impacts of contaminant exposure on Mediterranean coastal habitats. As study sites we selected two protected areas and two sites within industrial ports of the Ligurian Sea. Our results showed that the selected crab species is an excellent bioindicator. Individuals collected in sites with the highest levels of heavy metal pollution showed the highest signals of stress responses at both cellular and enzymatic levels, coupled with a high incidence of the parasite Sacculina carcini, a signal of impairment of their standard development and reproduction cycle. We could also prove that one of the selected marine protected areas showed the same intensity of impact as its adjacent port site. Our multidisciplinary approach proved to be a valuable tool to assess the environmental quality and health of protected and disturbed Mediterranean coastal environments and to inform efficient management and protection schemes for such habitats.

Application of Omics Tools in Designing and Monitoring Marine Protected Areas For a Sustainable Blue Economy

A key component of the global blue economy strategy is the sustainable extraction of marine resources and conservation of marine environments through networks of marine protected areas (MPAs). Connectivity and representativity are essential factors that underlie successful implementation of MPA networks, which can safeguard biological diversity and ecosystem function, and ultimately support the blue economy strategy by balancing ocean use with conservation. New “big data” omics approaches, including genomics and transcriptomics, are becoming essential tools for the development and maintenance of MPA networks. Current molecular omics techniques, including population-scale genome sequencing, have direct applications for assessing population connectivity and for evaluating how genetic variation is represented within and among MPAs. Effective baseline characterization and long-term, scalable, and comprehensive monitoring are essential for successful MPA management, and omics approaches hold great promise to characterize the full range of marine life, spanning the microbiome to megafauna across a range of environmental conditions (shallow sea to the deep ocean). Omics tools, such as eDNA metabarcoding can provide a cost-effective basis for biodiversity monitoring in large and remote conservation areas. Here we provide an overview of current omics applications for conservation planning and monitoring, with a focus on metabarcoding, metagenomics, and population genomics. Emerging approaches, including whole-genome sequencing, characterization of genomic architecture, epigenomics, and genomic vulnerability to climate change are also reviewed. We demonstrate that the operationalization of omics tools can enhance the design, monitoring, and management of MPAs and thus will play an important role in a modern and comprehensive blue economy strategy.