Science Advisory Report  2012/058

Results and recommendations from the Ecosystem Research Initiative – Newfoundland and Labrador’s Expanded Research on Ecosystem Relevant but Under-Surveyed Splicers

Summary

• In August 2007 a Regional Committee of scientists initiated a process aimed at filling knowledge gaps in the NL DFO Science program which evolved into the regional component of the DFO Ecosystem Research Initiative (ERI), the “Newfoundland and Labrador’s Expanded Research on Ecosystem-relevant but Under-surveyed Splicers” (NEREUS).
• Between 2008 and 2012, the ERI-NEREUS program added new or redesigned sampling components in DFO Research Vessel surveys, such as the collection and processing of acoustic information, implementation of a grab sampling program on the Grand Bank, a new scheme for sampling of stomach contents of key fish species, and expanded sampling of non-commercial species.
• The main outcomes of the ERI-NEREUS program, to date, include a description of status and trends in main forage fish species, as well as the structure and changes in the fish community; a characterization of main components of benthic communities; and an analysis of trophic interactions among key components of the NL marine community.
• Results of the grab sampling program conducted at 58 stations over three NAFO Divisions (3NLO) showed that a total of 12 phyla were represented with three phyla (Annelida, Arthropoda and Mollusca), accounting for 86% of all recorded taxa. Echinodermata dominated biomass (58% of total), particularly the sand dollar, Echinarachnius parma (69% of total echinoderm biomass). The overall biomass of 228 g/m2 recorded in the NEREUS program is within the range of previous studies.
• Preliminary analysis of hydroacoustic data collected during fall bottom trawl surveys during 2008 indicated that auxillary acoustic may be useful to estimate availability to the bottom trawl of at least two forage species (Capelin and Sand Lance). New information on spatial variation of biological characteristics and feeding of forage species was collected and described.
• During the late 1980s and early 1990s most of the fish community in the Newfoundland and Labrador shelves marine ecosystem collapsed; the exceptions were small benthivore fish and especially shellfish, whose biomass increased significantly. Even though this collapse is often associated primarily with Atlantic cod in the early 1990s, declines in several functional groups started in the early 1980s. The collapse was observed throughout the system and involved commercial and non-commercial species alike. Current levels of some fish functional groups are still well below pre-collapse levels.
• Trophic structure indicators clearly show a transition from a large fish community to one of shrimp and small fish.
• Long time series on condition are only available for some commercially important species and generally indicate that fish were in better condition in the 1980s and into the early 1990s; the mid 1990s and early 2000s appear to be a period of poor fish condition; and condition seems to have improved in the late 2000s.
• In the mid 1990s, the contribution of Capelin to the diet of fish predators was reduced, while that of shrimp increased. Diets of some fish predators on the Grand Bank have been dominated by Sand Lance in recent years. For smaller/younger predators, amphipods are an important prey.
• Fishing appears as a consistent and significant driver of the trajectories of five key fish species of the NL marine community during the early-mid 1980s to the mid 1990s, and still remains as an important driver in more recent times (mid 1990s to 2008) when fisheries have been targeting mainly shrimp and crab. Environmental variables also appear as significant drivers, but their effect is less consistent than that observed for fishing.
• A study examined the relationship between seasonal sea ice dynamics, capelin biomass and timing of spawning to probe the hypothesis that capelin is environmentally regulated via food availability. The study found evidence of a regime shift and indicates that ice dynamics are a major driver of capelin dynamics. These findings suggest regulation of energy flow is bottom-up.
• A study on the drivers of Northern Cod trajectory tested competing hypotheses for patterns in the variation of the Northern Cod stock biomass since 1985: the roles of fisheries removals, predation by harp seals, and the availability of capelin, which is a key prey for cod. Among the factors considered, patterns of variation in stock biomass of Northern Cod appear to be influenced by fisheries and the availability of capelin, but not by seal predation.
• Relevant information from ERI-NEREUS results should be explicitly incorporated into stock assessments whenever possible (e.g., effects on natural mortality) and could be used to assist managers in the formulation of appropriate ecosystem-related questions.
• Information from ERI-NEREUS could be used to address longer term strategic and conceptual questions in relation to sustainable management of ecosystem goods (e.g., fisheries yields) and services (e.g., biodiversity).
• Future policy development related to the ecosystem approach would benefit from Regional scientific knowledge and expertise. Good communication within Regions and between Regions and National Headquarters is key to the development of ecosystem approach policy and frameworks.
• Comprehensive monitoring is fundamental to continuing with an ecosystem approach to science, but there should be a cost-benefit analysis of collecting additional information from new sources.
• Analysis of existing data must be assigned the top priority in any further effort on this research program.
• Ecosystem-based management will require more data, and the development of new tools and approaches as compared with the traditional single-species approach to management. Therefore more dedicated resources and increased collaboration will be required.
• A stable funding source, including appropriate human resources, tools and equipment, is key to implementing an ecosystem research program on the level of ERI-NEREUS.
• Key recommendations for future directions include the re-establishment of a national ERI network, and conducting a national review of ERI programs. Such a review would allow the application of what was learned in ERI-NEREUS to other Regions, and vice versa.

This Science Advisory Report is from the Fisheries and Oceans Canada, Canadian Science Advisory Secretariat, (Regional advisory meeting of January 17-19, 2012 on Ecosystem Research Initiative (ERI) – NEREUS Program). Additional publications from this process will be posted as they become available on the DFO Science Advisory Schedule.

Complete document (PDF, 146 KB)

Accessibility Notice

This document is available in PDF format. If the document is not accessible to you, please contact the Secretariat to obtain another appropriate format, such as regular print, large print, Braille or audio version.