Biases in biodiversity: wide-ranging species are discovered first in the deep sea

Abstract

Calculating global estimates for total species richness is fraught by the uncertainty in estimating the number of species left to be discovered. The deep-sea is widely regarded as one of the largest sources of uncertainty in these calculations, since so much of this realm has not yet been explored. Most estimates of species left to be discovered are reliant on previous rates of species description, yet these rates are likely to be biased. One well-known bias from terrestrial studies is that wide-ranging species tend to be described earlier. To test this hypothesis for the deep sea, spatial data from the Ocean Biogeographic Information System (OBIS) were combined with taxonomic data from the World Register of Marine Species (WoRMS) to carry out a meta-analysis on all species records found below 300 m. Results show a historical bias in species descriptions, with wide-ranging species over-represented in our current catalogs of deep-sea species richness. This suggests that current estimates of deep-sea species richness underestimate the true proportion of narrow-ranged species and hence total species in the deep oceans.

Deep-Sea Mining With No Net Loss of Biodiversity—An Impossible Aim

“…While biodiversity loss is recognized as a major global environmental problem (Weikard, 2002), the importance of biodiversity in the deep ocean merits clarification, particularly given that most species (both prokaryotes and eukaryotes) remain undiscovered or unidentified (Higgs and Attrill, 2015;Sinniger et al, 2016;Shulse et al, 2017). Deep-sea biodiversity is valued both for the ecosystem services it provides and for underpinning the health of the oceans by enabling a range of ecological and evolutionary functions that are viewed as necessary to productive, sustainable ecosystems (Thurber et al, 2014).…”

Fine Scale Assemblage Structure of Benthic Invertebrate Megafauna on the North Pacific Seamount Mokumanamana

“…Operational time constraints at any feature, especially on remote locations, limits the number and length of surveys that can be planned, often resulting in little or no replication across environmental gradients such as depth or substrate. As such, while these surveys are good for providing an ecosystem snapshot and partial species lists for a given seamount, they are not able to provide replicate sampling within features for statistical tests to compare fauna among areas on a given seamount or often even between features (Rowden et al, 2010;Sautya et al, 2011;Higgs and Attrill, 2015).…”

Relating Depth and Diversity of Bivalvia and Gastropoda in Two Contrasting Sub-Arctic Marine Regions

“…The vast majority (91%) of marine benthic habitat lies below 200 m depth where darkness prevails and autotrophic activity is negligible (Kennish, 2000). Accessing the deep ocean is a very costly and logistically challenging endeavor, explaining why ecosystems in the deep sea remain insufficiently studied compared with shallow water or terrestrial systems (May and Godfrey, 1994;Higgs and Attrill, 2015). It is more urgent than ever to document and understand biodiversity patterns and ecological processes in deep-sea benthic ecosystems, as these systems, typified by environmental stability (Seibel and Walsh, 2003;Hofmann et al, 2011), limited food availability (Lutz et al, 2007) and low temperatures which limit rate processes (Childress, 1995), may be particularly sensitive to natural and human-induced environmental changes that are occurring at unprecedented rates (Crain et al, 2008;Gehlen et al, 2014;Rogers, 2015).…”