Thematic Goal 1: Sustainable Fisheries

Coastal Maine has experienced profound changes in its fisheries in the last century. Some fisheries have proven ecologically resilient (e.g., lobster), while others have collapsed (e.g., cod). Consequently, Maine’s marine resources are characterized by a mixture of species that are targets for restoration, sustainable harvest, aquaculture, or combinations thereof. There is an increasing number of  policy calls to employ ecosystem-based approaches to fisheries and aquaculture management, recognizing the broader community context in which fisheries are embedded. eDNA-based ecological inference represents a potentially transformative capacity to understand ecosystem baselines, interactions, and changes important to sustainable coastal fisheries and aquaculture. 

What population, community, and ecosystem processes, operating at various spatiotemporal scales (centuries to seasonal and local to macrosystem), both shape and are shaped by the stability and resilience of coastal fisheries? To help answer this question, Maine-eDNA researchers are implementing two key projects: 1. Examining the past, present and future of ecosystem-based restoration projects and 2. The other seeking to shed light on the larval black box of many invertebrates and algae.

The ecosystem-based restoration project will quantify and contextualize the trophic and ecosystem consequences of historical losses and recovery of anadromous river herring, an important restoration target linking coastal ecosystems. Their first objective is to use eDNA in lake sediments as an ecological time machine to reconstruct the historical and contemporary roles of river herring in the trophic cascades of multiple lake communities with different histories of fish extirpation and recovery. The second is to use metabarcoding approaches to quantify the specific coastal community interactions of river herring within a broader assemblage of ecologically similar secondary-consumers.

The larval black box project will find our researchers disentangling the larval supply-side from the post-settlement side of shellfish and macroalgal recruitment ecology to improve sustainable use of wild and cultured resources. They will relate scallop and mussel gamete/larval and kelp spore densities to eDNA concentration as a function of local broodstock abundance, spawning timing, and oceanic conditions. Along with relating spatiotemporal variability in lobster larval fate, abundance, settlement, and diet to eDNA-inferred community structure, our researchers will be closer to achieving their goal.

Through this work, we build eDNA capacity that spans the coastal gradient and a diversity of temporal and taxonomic scales. By conducting this research on species that are highly valued by Maine partners (alewife, lobster, and shellfish), we seek to adapt eDNA to a cooperative framework for ecosystem-based management of Maine’s aquatic natural resources.