International scientific collaboration is vital for supporting global and regional measures to protect marine biodiversity in and beyond national jurisdiction. While scientists and governments seem to agree that scientific cooperation is also needed to reduce global imbalances to explore and exploit marine biodiversity, progress in defining and assessing developing countries’ needs has been slow. This paper aims to identify some of those needs by mapping the global distribution of scientific publications from the marine biodiversity field from 1990 until 2018. We present bibliographic data gathered from the Web of Science Core Collection using network analysis and article meta-data to examine international cooperation patterns both within and across regions. We introduce a novel measure, ‘collaboration capital’, which, based on metrics derived from a co-authorship network, attempts to gauge how valuable other actors in the network perceive the collaboration with an actor. Our data reveal that the US and Europe’s usual suspects allocate a significant proportion of collaboration capital from all regions. In turn, regional research networks in Asia, South America, and Africa are severely underdeveloped. These results suggest that measures to strengthen scientific collaboration within regions and between neighboring countries may contribute to strengthening regional research networks, for instance, by encouraging large emerging economies such as Brazil and China to become leaders in their regions in this respect. We conclude that capacity-building measures, such as discussed in current marine biodiversity negotiations, should foster regional scale cooperation efforts.
Fishes are known to use deep-sea coral and sponge (DSCS) species as habitat, but it is uncertain whether this relationship is facultative (circumstantial and not restricted to a particular function) or obligate (necessary to sustain fish populations). To explore whether DSCS provide essential habitats for demersal fishes, we analyzed 10 years of submersible survey video transect data, documenting the locations and abundance of DSCS and demersal fishes in the Southern California Bight (SCB). We first classified the different habitats in which fishes and DSCS taxa occurred using cluster analysis, which revealed four distinct DSCS assemblages based on depth and substratum. We then used logistic regression and gradient forest analysis to identify the ecological correlates most associated with the presence of rockfish taxa (Sebastes spp.) and biodiversity. After accounting for spatial autocorrelation, the factors most related to the presence of rockfishes were depth, coral height, and the abundance of a few key DSCS taxa. Of particular interest, we found that young-of-the-year rockfishes were more likely to be present in locations with taller coral and increased densities of Plumarella longispina, Lophelia pertusa, and two sponge taxa. This suggests these DSCS taxa may serve as important rearing habitat for rockfishes. Similarly, the gradient forest analysis found the most important ecological correlates for fish biodiversity were depth, coral cover, coral height, and a subset of DSCS taxa. Of the 10 top-ranked DSCS taxa in the gradient forest (out of 39 potential DSCS taxa), 6 also were associated with increased probability of fish presence in the logistic regression. The weight of evidence from these multiple analytical methods suggests that this subset of DSCS taxa are important fish habitats. In this paper we describe methods to characterize demersal communities and highlight which DSCS taxa provide habitat to demersal fishes, which is valuable information to fisheries agencies tasked to manage these fishes and their essential habitats.
Species composition plays a key role in ecosystem functioning. Theoretical, experimental and field studies show positive effects of biodiversity on ecosystem processes. However, this link can differ between taxonomic and functional diversity components and also across trophic levels. These relationships have been hardly studied in planktonic communities of coastal upwelling systems. Using a 28-year time series of phytoplankton and zooplankton assemblages, we examined the effects of phytoplankton diversity on resource use efficiency (RUE, ratio of biomass to limiting resource) at the two trophic levels in the Galician upwelling system (NW Iberian peninsula). By fitting generalized least square models, we show that phytoplankton diversity was the best predictor for RUE across planktonic trophic levels. This link varied depending on the biodiversity component considered: while the effect of phytoplankton richness on RUE was positive for phytoplankton RUE and negative for zooplankton RUE, phytoplankton evenness effect was negative for phytoplankton RUE and positive for zooplankton RUE. Overall, taxonomic diversity had higher explanatory power than functional diversity, and variability in phytoplankton and zooplankton RUE decreased with increasing phytoplankton taxonomic diversity. Phytoplankton used resources more efficiently in warmer waters and at greater upwelling intensity, although these effects were not as strong as those for biodiversity. These results suggest that phytoplankton species numbers in highly dynamic upwelling systems are important for maintaining the planktonic biomass production leading us to hypothesize the relevance of complementarity effects. However, we further postulate that a selection effect may operate also because assemblages with low evenness were dominated by diatoms with specific functional traits increasing their ability to exploit resources more efficiently.
Most literature exploring the biological effects of ocean acidification (OA) has focused on macroscopic organisms and far less is known about how marine microbial communities will respond. Studies of OA and microbial community composition and diversity have examined communities from a limited number of ocean regions where the ambient pH is near or above the global average. At San Juan Island (Salish Sea), a region that experiences naturally low pH (average = 7.8), the picoplankton (cell diameter is 0.2–2μm) community was predicted to show no response to experimental acidification in a three-week mesocosm experiment. Filtered seawater mesocosms were maintained via semicontinuous culturing. Three control mesocosms were maintained at pH 8.05 and three acidified mesocosms were maintained at pH 7.60. Total bacteria was quantified daily with a flow cytometer. Microbial communities were sampled every two days via filtration followed by DNA extraction, 16S rRNA amplification, and MiSeq sequencing. There was no significant difference in total bacteria between pH treatments throughout the experiment. Acidification significantly reduced Shannon’s diversity over time. During the final week of the experiment, acidification resulted in a significant decrease in Shannon’s diversity, Faith’s phylogenetic distance, and Pielous’s Evenness. ANCOM results revealed four bacterial ASVs (amplicon sequence variants), in families Flavobaceriaceae and Hyphomonadaceae that significantly decreased in relative frequency under acidification and two bacterial ASVs, in families Flavobacteriaceae and Alteromonadaceae, that significantly increased under acidification. This is the first OA study on the microbial community of the Salish Sea, a nutrient rich, low pH region, and the first of its kind to report a decrease in both picoplankton richness and evenness with acidification. These findings demonstrate that marine microbial communities that naturally experience acidic conditions are still sensitive to acidification.
Coral reefs are widely regarded as one of the top science and conservation priorities globally, as previous research has demonstrated that these ecosystems harbor an extraordinary biodiversity, myriad ecosystem services, and are highly vulnerable to human stressors. However, most of this knowledge is derived from studies on nearshore and shallow-water reefs, with coral reef ecosystems remaining virtually unstudied in marine areas beyond national jurisdiction (ABNJ), commonly known as the high seas. We reviewed information on the spatial distribution of reef-building corals throughout their depth range, and compiled a total of 537,782 records, including 116 unique records from ABNJ at depths between 218–5,647 m. The majority of reef-building coral records in ABNJ were in association with geomorphological features that have steep topographies. These habitats, which include escarpments, seamounts, and submarine ridges accounted for >74% of the records in international waters. Such geomorphological features, particularly those that occur within close proximity to the sea surface, should be prioritized for future scientific exploration. The majority of the reef-building coral records in ABNJ (>77%) were recorded in unprotected waters, and this study discusses the challenges and opportunities for protecting marine biodiversity in ABNJ. Finally, this study offers a definition of high seas coral reefs, and provides a framework to better understand and conserve these fragile ecosystems.
Ecosystem-based management (EBM) is a potential antidote to the alleviation of multiple stressors in highly-valued and contested marine environments. An understanding of the magnitude and drivers of past ecosystem changes can inform the development of realistic ecological and social outcomes for different places. These goals should aim to increase the ecological health and resilience of coastal ecosystems and their connected land- and sea-scapes by minimising anthropogenic disturbances. To address knowledge gaps, we present a marine historical synthesis of the Marlborough Sounds in New Zealand's South Island. These rias are strongly coupled to the surrounding land and inland river catchments. We took an integrated approach by examining effects of land use change on coastal ecosystems, along with case studies of the effects of exploitation on foundational marine species. We found that ecosystems have gone through a series of transformations since Māori settlement ca. 700 years ago, with localised extirpations of marine megafauna, overharvesting of exploited species, and disruption to ecological functioning through ongoing clearfelling of terrestrial and marine biogenic communities since European settlement in the 1800s. There has been a decline from great abundance of marine life to relative scarcity, which is currently evident to local people in increased effort and reduced allowable catches of fish and shellfish. Recovery of biodiversity in the short-term within the Marlborough Sounds is uncertain, given ongoing multiple and interacting stressors from unsustainable land-use and over-exploitation of marine life. Lifting baselines are possible but will require significant changes to land and marine management to restore ecological health and enhance resilience in the face of climate change. Increased marine protection, regeneration of biodiverse biogenic habitats, spatial fishing measures to increase predators of sea urchins, stricter regulation of plantation forestry and a replanting prohibition in critical erosion source areas, are all needed within an EBM framework. Large experimental areas are proposed to develop, test and integrate different management techniques, and to facilitate community understanding, participation, and support for the transition to EBM.
Many important areas identified for conservation priorities focus on areas of high species richness, however, it is unclear whether these areas change depending on what aspect of richness is considered (e.g. evolutionary distinctiveness, endemicity, or threatened species). Furthermore, little is known of the extent of spatial congruency between biodiversity measures in the marine realm. Here, we used the distribution maps of all known marine sharks, rays, and chimaeras (class Chondrichthyes) to examine the extent of spatial congruency across the hotspots of three measures of species richness: total number of species, evolutionarily distinct species, and endemic species. We assessed the spatial congruency between hotspots considering all species, as well as on the subset of the threatened species only. We consider three definitions of hotspot (2.5%, 5%, and 10% of cells with the highest numbers of species) and three levels of spatial resolution (1°, 4°, and 8° grid cells). Overall, we found low congruency among all three measures of species richness, with the threatened species comprising a smaller subset of the overall species patterns irrespective of hotspot definition. Areas of congruency at 1° and 5% richest cells contain over half (64%) of all sharks and rays and occurred off the coasts of: (1) Northern Mexico Gulf of California, (2) USA Gulf of Mexico, (3) Ecuador, (4) Uruguay and southern Brazil, (5) South Africa, southern Mozambique, and southern Namibia, (6) Japan, Taiwan, and parts of southern China, and (7) eastern and western Australia. Coarsening resolution increases congruency two-fold for all species but remains relatively low for threatened measures, and geographic locations of congruent areas also change. Finally, for pairwise comparisons of biodiversity measures, evolutionarily distinct species richness had the highest overlap with total species richness regardless of resolution or definition of hotspot. We suggest that focusing conservation attention solely on areas of high total species richness will not necessarily contribute efforts towards species that are most at risk, nor will it protect other important dimensions of species richness.
The scientific literature available on deep-sea biodiversity is ample and covers a wide array of objectives, geographic areas, and topics. It also explores the links between ecosystem functioning and productivity as well as modeling, management, and exploitation. New statistical analytical tools now allow the comprehensive monitoring of the status of deep-sea research to highlight global research topics and their trends, which deserve further development and economic investments. Here, we used a science mapping approach to provide a global and systematic bibliometric synthesis of these current research topics and their trends to identify the size, growth, trajectory, and geographic distribution of scientific efforts as well as to highlight the emerging topics. A total of 1287 deep-sea biodiversity publications were retrieved from the Scopus database from 1993 to the present. Both established and emerging research topics were identified: (i) biogeochemical, microbial, and molecular analyses; (ii) biodiversity assessments; (iii) ecosystem conservation and management; and, finally, (iv) zoology and taxocoenosis. The temporal change in research activity (which was assessed by subdividing publications into blocks from 1993 to 2010 and 2011 to 2019) demonstrated that the “biogeochemical, microbial, and molecular analyses” cluster was not present from 1993 to 2010 since it was included in the cluster for “biodiversity assessments,” which it eventually diverged from in the following couple of decades. The United States took the dominant role in research, followed by the United Kingdom; Germany and France were also evidenced. China was particularly associated with the United States.
A 2012 Expert Panel Report on marine biodiversity by the Royal Society of Canada (RSC) concluded that Canada faced significant challenges in achieving sustainable fisheries, regulating aquaculture, and accounting for climate change. Relative to many countries, progress by Canada in fulfilling international obligations to sustain biodiversity was deemed poor. To track progress by Canada since 2012, the RSC struck a committee to track policy and statutory developments on matters pertaining to marine biodiversity and to identify policy challenges, and leading options for implementation that lie ahead. The report by the Policy Briefing Committee is presented here. It concluded that Canada has made moderate to good progress in some areas, such as prioritization of oceans stewardship and strengthening of the evidentiary use of science in decision-making. Key statutes were strengthened through amendments, including requirements to rebuild depleted fisheries (Fisheries Act) and new means of creating marine protected areas (Oceans Act) that allowed Canada to exceed its international obligation to protect 10% of coastal and marine areas by 2020. Public release of mandate letters has strengthened ministerial accountability. However, little or no progress has been made in reducing regulatory conflict with Fisheries and Oceans Canada (DFO), decreasing ministerial discretion under the Fisheries Act, clarifying the role of science in sustainable fisheries policy, and accounting for climate change. Five future policy challenges are identified: (1) Ensure climate change impacts and projections are incorporated into ocean-related decision making and planning processes; (2) Resolve DFO’s regulatory conflict to conserve and exploit biodiversity; (3) Limit ministerial discretionary power in fisheries management decisions; (4) Clarify ambiguities in how the Precautionary Approach is applied in sustainable fisheries policy; and (5) Advance and implement marine spatial planning. Since 2012, there has been progress in recovering and sustaining the health of Canada’s oceans. Failure to further strengthen biodiversity conservation threatens the capacity of Canada’s oceans to provide ecosystem services that contribute to the resilience of marine life and the well-being of humankind. Unprecedented and enduring changes in the ocean caused by climate change have made the achievement of meaningful progress all the more urgent.
The great anthropogenic alterations occurring to carbon availability in the oceans necessitate an understanding of the energy requirements of species and how changes in energy availability may impact biodiversity. The deep-sea floor is characterized naturally by extremely low availability of chemical energy and is particularly vulnerable to changes in carbon flux from surface waters. Because the energetic requirements of organisms impact nearly every aspect of their ecology and evolution, we hypothesize that species are adapted to specific levels of carbon availability and occupy a particular metabolic niche. We test this hypothesis in deep-sea, benthic invertebrates specifically examining how energetic demand, axes of the metabolic niche, and geographic range size vary over gradients of chemical energy availability. We find that benthic invertebrates with higher energetic expenditures, and ecologies associated with high energy demand, are located in areas with higher chemical energy availability. In addition, we find that range size and location of deep-sea, benthic species is determined by geographic patterns in chemical energy availability. Our findings indicate that species may be adapted to specific energy regimes, and the metabolic niche can potentially link scales from individuals to ecosystems as well as adaptation to patterns in biogeography and biodiversity.