Juvenile Sockeye and Oceanographic Monitoring Project
For the second year running, Salmon Coast hosted Simon Fraser University PhD candidate Sean Godwin and his team as they ran the Johnstone Strait portion of the Hakai Institute’s Salmon Early Marine Survival Program (SEMSP). The SEMSP is a multi-region, 4-year initiative aiming to tackle some of the big questions about the early marine survival of juvenile salmon. The Program involves researchers from SFU, UBC, UVic, UoT, and DFO, including Salmon Coast’s own Sean Godwin, Luke Rogers, and Martin Krkosek.
Sean and his crew sampled juvenile salmon throughout Johnstone Strait during the spring outmigration period and ran an oceanographic monitoring program at three key locations in the same region. Together, the salmon collections and oceanographic data will help tease apart the factors governing juvenile salmon survival in this region. Sean’s portion of the project will investigate how regions with very little prey – like Johnstone Strait – influence the effects of sea lice on sockeye salmon. We’ve had another successful sampling season in 2016 and look forward to welcoming the SEMSP crew again in Spring 2017.
Salmon Virus Study
University of Toronto MSc student Dylan Shea returned to Salmon Coast this spring for another season of sample collection to test for salmon viruses in the water column near active and fallow salmon farms. He and his team also collected samples in the Discovery Islands, working out of the Hakai Research Institute’s Quadra Lab.
Trapper’s Cabin Project
The Musgamagw Dzawada’enuxw Tribal Council (MDTC) is revitalizing traditional, family-owned trap lines throughout the territories of the four MDTC nations. One of the first initiatives was constructing a simple split-cedar cabin, built in the tradition of trapper’s and hand-logger’s cabins of this coast. Thanks to an amazing all woman crew, donation of a beautiful cedar log by the Kwikwasut’inuxw Haxwa’mis First Nation (KHFN), and invaluable guidance from Billy Proctor, the first cabin was a great success. Amidst lots of laughter and learning the cabin was built in April 2016 in Echo Bay, on an ancient Musgamagw Dzawada’enuxw village site where Echo Bay school used to be before being dismantled in 2014. One of the crew even went to school there! Using only a chainsaw and hand tools the crew built the cabin over two weeks. The rustic cabin provides a place for people to enjoy time outside within MDTC territory and is open to the public.
While stories were shared and new friendships made, the process was filmed by documentarian Lindsey Mae Willie of the Dzawada’enuxw and audio recorded by acoustic ethnographer Jennifer Schine, a Salmon Coast board member. The film and audio are being used to create educational materials for Nation members.
Salmon Coast Field Station was excited to host the project crew – Julia McIntyre-Smith, Jennifer Schine, Scott Rogers, Dorienne Prevost, Alana Coon, and Lindsey Mae Willie – and grateful for the opportunity to work with the MDTC. This project is one component of a larger Nation-led vision that includes constructing a network of traditional cabins and smokehouses, providing trapping certification courses, and opportunities to train community members in construction and documentation methods.
The Trapper’s Cabin Project acknowledges support from The Firelight Group, Sea to Cedar, and Tides Canada. For further information about the Project please contact the Musgamagw Dzawada’enuxw Tribal Council: www.mdtc.ca.
Comparing Stock Assessment Methods for Pacific Herring
University of Toronto researchers are reviewing stock assessment methods for Pacific herring. Stocks of Pacific herring are in decline in three of their five major regions of distribution in BC despite fishery closures during years of low abundance. This project seeks to understand the causes of these declines by quantifying support for various alternative hypotheses; for example, whether declines are driven by competition, disease, climate, and/or fishing. By reviewing stock assessments across different regions, researchers aim to determine whether the selected methodologies produce stock estimates directly comparable in analyses of herring population dynamics.
Bioeconomic Dynamics of Fisheries and Aquaculture
Melissa Orobko recently completed her Master of Science degree at the University of Toronto investigating the relationship between wild fisheries and aquaculture. A shortfall in wild seafood supply to meet growing demand has led to the rapid growth of farmed fish populations. Wild fisheries and aquaculture can interact ecologically (e.g. through sharing of diseases) as well as economically by supplying similar products to markets. Melissa’s research involved developing and analysing mathematical bioeconomic models of fisheries and aquaculture, and showed that alternate stable states of either aquaculture or fishery dominance are likely to exist, and transitions between the states can be abrupt and difficult to reverse. Coexistence of fisheries and aquaculture is therefore either unstable or requires ecological feedbacks be kept below a threshold. Empirical records of salmonid production are in qualitative agreement with model outputs, implying that careful management is required to sustain wild fisheries into the future.
Modelling Spread of Sea Lice between Salmon Farms
MSc candidate Peter Harrington of the University of Alberta is investigating the spread of sea lice between salmon farms. In the Broughton Archipelago, sea lice can spread between salmon farms either by hitching a ride on migrating wild salmon or simply by floating through the ocean as nauplii. Therefore, if a single farm experiences an outbreak of lice and subsequently treats the farm to remove the infestation, some lice will have already reached other farms before the treatment has taken effect. This project uses mathematical models to examine how times for first passage of sea lice past farms are influenced by different environmental factors, such as extent of mixing in the ocean due to tides or size of salmon farm. The goal is to see how quickly lice from an outbreak will spread to other farms, with a view to adjusting treatment protocols to minimize subsequent outbreaks and dispersal. Because many salmon farms in Broughton Archipelago are owned and operated by a single company, this research has significant potential to inform local management practices.
Links between Juvenile Salmon Leaping Behaviour and Presence of Sea Lice?
Undergraduate student Emma Atkinson from Simon Fraser University in Vancouver sought to investigate questions surrounding the leaping behaviour of juvenile salmon. Juvenile salmon leap frequently, but no one knows why. One key hypothesis is that they may leap to dislodge ectoparasites such as sea lice, which is likely to be energetically costly for the salmon and potentially compromise their health and survival. Building on a study published in 2007 where juvenile salmon infected with sea lice exhibited a 14-fold increase in leaping behaviour compared to uninfected fish in a laboratory setting (Webster et al. 2007), this ongoing project is examining under natural conditions whether leaping behaviour is effective at dislodging sea lice. Six multi-day trials were conducted and post-trial louse loads were measured and compared on fish free to jump versus fish prevented from jumping. Data are currently being analysed to increase understanding about this aspect of juvenile salmon behaviour.
SLICE: Policy & Regulation
Undergraduate student Griffin Kelly from the University of Toronto examined use and regulation of SLICE, an insecticide used by operators of salmon farms to manage sea lice populations on their farms. A main area of interest was the impact of SLICE use on natural resources and environment legislation. The researched assessed non-chemical alternatives to SLICE, such as incorporating cleaner fish and filter feeders into farms to reduce lice levels, as well as the importance of collaborative monitoring practices and the need for coordinated regional policies for lice management. In addition to policy research, a series of SLICE efficacy bioassays were conducted on sea lice collected from wild juvenile salmon. These data will be compared to results for previous and future bioassays by Salmon Coast Field Station researchers in order to monitor potential resistance to SLICE.
Species-specific Leaping Behaviour by Salmon
Many observers of adult Pacific salmon are convinced each species exhibits unique leaping behaviour. However, it is not known whether juvenile salmon also exhibit unique leaping behaviours. Undergraduate student Jack Goldman from the University of Toronto used slow-motion video imagery to record and classify leaping by sockeye, pink, and chum salmon smolts, and determine whether species of juvenile salmon can be identified by unique leaping behaviour or characteristics. Initial data indicated many similarities between species for metrics such as roll and sideways rotation, wag, leap height, and body orientation at water exit and re-entry. Further analysis of other leap characteristics will aim to identify distinguishable leaping behaviour between species.
Sea Louse Host Selection
From years of field observations Salmon Coast researchers have noted that compared to pink salmon and chum salmon sampled in the Broughton Archipelago, sockeye salmon migrating through Johnstone Straight have relatively high numbers of Caligus clemensi sea lice. Caligus spp sea lice are marine ectoparasites occurring naturally on many species of wild fish. This preliminary research, conducted by undergraduate student Yijun (Lily) Xiong of the University of Toronto, explored whether Caligus are likely to be more abundant in the southern waters sockeye migrate from, and/or whether these lice prefer sockeye salmon to pink or chum. A small-scale pilot study of host selection by C. clemensi found that lice attached faster and in higher numbers to sockeye salmon than to pink salmon, suggesting possible preference and the value of further investigation.