Rapid assessment of an ocean warming hotspot reveals “high” confidence in potential species’ range extensions

L.M Robinson,D.C Gledhill,N.A Moltschaniwskyj,A.J Hobday,S Frusher,N.barrett N.Barrett,J Stuart-Smith,G.T Pecl

doi:10.1016/j.gloenvcha.2014.12.003

Abstract

Shifts in species’ ranges are one of the most frequently reported and globally ubiquitous impacts of climate change, with rates of movement being particularly high in the sea. The arrival of multiple range extending species can cause serious issues for natural resource managers; some species threaten ecosystem function while others present social and/or economic opportunities. An early indication of which species are potentially extending their ranges can provide useful guidance for managers regarding future investments in impact assessment, monitoring or potential management intervention. Given that scientific monitoring data on potential range shifting species are often sparse in the marine environment a rapid assessment that utilises and assimilates disparate data sources that vary in quality, quantity and collection methods is needed. Off the east coast of Tasmania surface waters have been warming at almost four times the global average and dozens of species range shifts have already been documented. Building on existing methods used in the early detection of invasive species, we developed a cost-effective and rapid screening assessment tool that uses monitoring data from a variety of sources, particularly from the citizen science program Redmap, to classify levels of confidence in potential range extensions over a three year time period (2009–2012) for a variety of marine species. From our assessment of 47 species, eight were classified with “high” confidence as potentially extending their ranges. The “high” confidence classification of these species suggests they should be a priority when investigating potential ecosystem and socio-economic impacts.

Highlights

Despite lower rates of ocean warming over the past 50 years compared to terrestrial environments, both climate velocities and shifts in the seasonal timing of temperatures have been higher in the ocean than on land (Burrows et al, 2011)
Confidence in the historical poleward range boundary was classified for all 47 Range Extension Database and Mapping Project’ (Redmap) species, but the results from 19 species that were assessed for evidence for consistent out-of-range observations are presented (Table 1)
The method has been applied in a global warming marine hotspot off the east coast of Tasmania (Hobday and Pecl, 2014) using observations predominately collected as part of the citizen science program Redmap

Summary

Introduction

Despite lower rates of ocean warming over the past 50 years compared to terrestrial environments, both climate velocities (i.e. geographic shifts in isotherms) and shifts in the seasonal timing of temperatures have been higher in the ocean than on land (Burrows et al, 2011) This may explain why the marine environment is where some of the greatest ecological impacts of climate change are being observed (Poloczanska et al, 2013). Most studies that have detected extensions in species ranges have used data intensive quantitative methods that require observations collected from a broad geographic area and over multi-decadal periods (Przeslawski et al, 2012). Rapid screening assessments of potential range extending marine species need to accommodate limited observations/information

Methods

Results

Discussion

Conclusion