Grand challenges in marine conservation and sustainable use

The oceans contain the most biologically diverse ecosystems on earth, yet in comparison to terrestrial systems, our understanding and protection of these habitats and their species is lagging (Hendriks et al., 2006; Richardson and Poloczanska, 2008; Polidoro et al., 2009; McCauley et al., 2015). Given the critical ecosystem services that the oceans provide, such as food security, coastal defense, and climate regulation, and with much of the oceans considered overexploited and potentially beyond recovery (Neubauer et al., 2013; Dulvy et al., 2014; Selig et al., 2014), protecting and sustainably using the ocean’s resources is a major issue for human well-being. Nearly all of the drivers of biodiversity loss are anthropogenic, and with all studied marine ecosystems affected by human influence (Halpern et al., 2008; Butchart et al., 2010), reducing the threats tomarine systems should be within our control. Yet the pressures from human population growth are set to rise and that further exploitation of the ocean’s resources will occur is without a doubt. The overarching grand challenge then is to maintain biodiversity, protect ecosystems andmanage the sustainable extraction of these resources. With this being such a vast topic, I have chosen to focus here on the challenge of the lack of data on our ability to assess and prioritize marine species or ecosystems. Although a recent study of the scientific literature by Borja (2014), illustrates the dramatic increase in the number of articles including the words “marine ecosystems” (in the abstract, title, or keywords) over the past decade, and a similar rise is seen if we repeat the above exercise with “marine conservation” as the search term, several studies have highlighted the lack of marine conservation articles in both general conservation and aquatic focused journals (Levin and Kochin, 2004; Hendriks et al., 2006; Parsons, 2014), particularly those of high impact. Whether this is a result of the difficulty and additional expense of working in the marine environment, a lack of perceived interest by those working in terrestrial systems, or a lack of available funding is a matter of debate (Norse and Crowder, 2005; Richardson and Poloczanska, 2008), but recent data from the IUCN would suggest that lack of data is a major issue for accurate species and habitat assessments (IUCN, 2014). If we don’t know the status of a species or ecosystem, how can we assess the impact of a threat? As the IUCN celebrates 50 years of the Red List of Threatened Species, it has a goal to more than double the number of species assessed from 76,199 (IUCN, 2014) to over 160,000 by 2020. This is still less than 10% of described species and highlights the need to acquire data for key species assessments. In particular, there is a need to focus on the marine environment, making up fewer than 13% (9608 species) of assessed species, with 69% being terrestrial (52,602) and 34% (25,785) freshwater species. Although 29% of all assessed species are listed in the threatened categories [Critically Endangered (CR), Endangered (E) and Vulnerable (V)], in the marine realm only 11% of assessed species are listed as threatened. A closer look at the data however, shows that 25% of all marine species assessed are listed as Data Deficient (DD, meaning insufficient data to make an accurate assessment), in comparison to 12% of terrestrial species (and 17% of all species assessed). These DD species need to remain a priority and be treated as if they were in the threatened categories until data are available for accurate classification (McCauley et al., 2015; Parsons et al., in press), this is particularly important for long-lived species that need decades of monitoring before accurate assessments can be made. Of the marine species that are currently included on the IUCN Red List there is a clear bias toward vertebrates, making up 68% of those assessed, with 30% invertebrates and only 2% plants (Schipper et al., 2008; Polidoro et al., 2009; IUCN, 2014). A similar bias is, not surprisingly, seen in the scientific literature, toward marine megavertebrates and coastal habitats and ecosystems (McClenachan et al., 2012), both easier to assess (especially air breathers and those that haul out or breed on land) and potentially more likely to gain conservation support and funding. Species that haul out or breed on land have also however, been shown to have a greater risk of becoming threatened (McCauley et al., 2015). Given that we are unlikely to ever have all the data we want to make informedmanagement decisions it is often necessary to focus efforts on gathering data on species that are considered to be indicative of the state of an ecosystem (Maxwell et al., 2013) or on social science studies to help to prioritize our efforts (Maxwell et al., 2014). Adapting the existing IUCN Red List species criteria to assess marine ecosystems, Jackson (2008) has suggested that Coral Reefs and Estuaries and Coastal Seas should be listed as the most critically endangered marine ecosystems. Perhaps it is no surprise that the status of ocean ecosystems (Jackson, 2008) reduces with