There is long-standing ecological and socioeconomic interest in what controls the diversity and productivity of ecosystems. That focus has intensified with shifting environmental conditions associated with accelerating climate change. The U.S. Northeast Shelf (NES) is a well-studied continental shelf marine ecosystem that is among the more rapidly warming marine systems worldwide. Furthermore, many constituent species have experienced significant distributional shifts. However, the system response of the NES to climate change goes beyond simple shifts in species distribution. The fish and macroinvertebrate communities of the NES have increased in species diversity and overall productivity in recent decades, despite no significant decline in fishing pressure. Species distribution models constructed using random forest classification and regression trees were fit for the dominant species in the system. Over time, the areal distribution of occupancy habitat has increased for approximately 80% of the modeled taxa, suggesting most species have significantly increased their range and niche space. These niche spaces were analyzed to determine the area of niche overlap between species pairs. For the vast majority of species pairs, interaction has increased over time suggesting greater niche overlap and the increased probability for more intense species interactions, such as between competitors or predators and prey. Furthermore, the species taxonomic composition and size structure indicate a potential tropicalization of the fish community. The system and community changes are consistent with the view that the NES may be transitioning from a cold temperate or boreal ecoregion to one more consistent with the composition of a warm temperate or Carolinian system.

Item Type:	Refereed Article
Keywords:	trophic level, fisheries, species distribution model, climate change, species interactions, niche overlap, biodiversity, habitat
Research Division:	Environmental Sciences
Research Group:	Climate change impacts and adaptation
Research Field:	Ecological impacts of climate change and ecological adaptation
Objective Division:	Animal Production and Animal Primary Products
Objective Group:	Fisheries - wild caught
Objective Field:	Wild caught fin fish (excl. tuna)
UTAS Author:	Watson, RA (Professor Reginald Watson)
ID Code:	136222
Year Published:	2019
Web of Science® Times Cited:	24
Deposited By:	Fisheries and Aquaculture
Deposited On:	2019-12-06
Last Modified:	2020-05-13
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