Comparing and synthesizing quantitative distribution models and qualitative vulnerability assessments to project marine species distributions under climate change

Abstract

Species distribution shifts are a widely reported biological consequence of climate-driven warming across marine ecosystems, creating ecological and social challenges. To meet these challenges and inform management decisions, we need accurate projections of species distributions. Quantitative species distribution models (SDMs) are routinely used to make these projections, while qualitative climate change vulnerability assessments are becoming more common. We constructed SDMs, compared SDM projections to expectations from a qualitative expert climate change vulnerability assessment, and developed a novel approach for combining the two methods to project the distribution and relative biomass of 49 marine species in the Northeast Shelf Large Marine Ecosystem under a "business as usual" climate change scenario. A forecasting experiment using SDMs highlighted their ability to capture relative biomass patterns fairly well (mean Pearson's correlation coefficient between predicted and observed biomass = 0.24, range = 0-0.6) and pointed to areas needing improvement, including reducing prediction error and better capturing finescale spatial variability. SDM projections suggest the region will undergo considerable biological changes, especially in the Gulf of Maine, where commercially-important groundfish and traditional forage species are expected to decline as coastal fish species and warmerwater forage species historically found in the southern New England/Mid-Atlantic Bight area increase. The SDM projections only occasionally aligned with vulnerability assessment expectations, with agreement more common for species with adult mobility and population growth rates that showed low sensitivity to climate change. Although our blended approach tried to build from the strengths of each method, it had no noticeable improvement in predictive ability over SDMs. This work rigorously evaluates the predictive ability of SDMs, quantifies expected species distribution shifts under future climate conditions, and tests a new

Seasonality and Life History Complexity Determine Vulnerability of Dungeness Crab to Multiple Climate Stressors

“…Species‐specific vulnerability assessments can also be used to help design multi‐stressor experiments through the identification of key life stages and stressor targets (Hare et al., 2016). Although risk and vulnerability assessments have been criticized for only producing relative rankings that lack spatial granularity and are difficult to validate (Allyn et al., 2020), recent work has improved the quantitative, spatial, and uncertainty aspects of these methods (Hodgson et al., 2016; Stortini et al., 2015).…”

Climate impacts on the Gulf of Maine ecosystem

“…Projected warming also affects thermal habitats for species occurring in the Gulf of Maine, and three studies have provided species distribution projections for the Gulf of Maine and the surrounding region. Allyn et al (2020) used CMIP5 projections for 2050 that are in the middle range of the Brickman et al (2021) projections. Kleisner et al (2017) and Shackell et al (2014) used temperature projections that are higher than the Brickman et al projections.…”

“…9(1) page 6 of 18 Pershing et al: Climate Impacts in the Gulf of Maine Ecosystem more southern species (e.g., summer flounder-Paralichthys dentatus, striped bass-Morone saxatilis, bluefish-Pomatomus saltatrix, smooth dogfish-Squalus acanthias). As these southern species move northward in response to rising ocean temperatures, they are expected to become more prevalent in the Gulf of Maine by 2050 (Allyn et al, 2020). Projections tailored to individual species indicate more nuanced ways in which warming may affect suitable habitats and species distributions.…”

“…Empirical species distribution models give a range of predictions for how lobster distribution may change in the future. Multiple species distribution models indicate that suitable thermal habitat for lobsters in Gulf of Maine and Canadian Maritime waters will increase (Shackell et al, 2014;Kleisner et al, 2017;Morley et al, 2018;Greenan et al, 2019;Tanaka et al, 2020), but one study projects modest biomass declines over the distribution of lobster in the Gulf of Maine (Allyn et al, 2020). These studies vary substantially in the data sources and algorithms used to build and validate the models and in the warming scenarios used.…”

An assessment of marine, estuarine, and riverine habitat vulnerability to climate change in the Northeast U.S.

“…In some cases, significant research has advanced our understanding of the effects of climate change on individual habitats, or a single component of habitat. For example, many studies have investigated shifting thermal habitat and its effects on species distributions [ 10 – 15 ]. Other studies have explored the impacts of projected changes in the climate on living habitats such as corals [ 16 , 17 ], mollusks [ 18 – 21 ], seagrasses [ 22 – 24 ], and coastal wetlands [ 25 – 28 ].…”