0
Article Tier 2 Marine & Wildlife Sign in to save

The anthropogenic influence of shellfish aquaculture and microplastics on juvenile Pacific salmon on the east coast of Vancouver Island

2016

AI summary Read the abstract

Good news for salmon (and seafood lovers): researchers studying young Pacific salmon near shellfish farms on Vancouver Island found that oyster and clam farming doesn't harm baby salmon, in fact, one species actually did better near these farms. The salmon did contain tiny bits of microplastic (about 1 per fish), but the levels were low compared to other studies, suggesting that, at least for now, these coastal farms and plastic pollution aren't posing an immediate threat to salmon populations that many communities and diets depend on. Still, scientists recommend continued monitoring since coastal development and plastic pollution are

In the northeast Pacific, salmon are an integral part of ecology, economics and culture. Nearshore areas, where juvenile salmon reside upon leaving their natal streams, are important habitat during a critical time where growth can determine overall survivorship. With the rise in human development in coastal areas, these valuable habitats are becoming increasingly modified, however, the ecological ramifications are not fully understood. This study focuses on two types of anthropogenic influence including shellfish aquaculture, which modifies intertidal areas by adding structures such as intertidal fencing and anti-predator nets, and plastic marine pollution in the form of microplastics. We beach seined at sites within an area extensively modified for shellfish aquaculture (Baynes Sound) to examine juvenile salmon abundance, condition, feeding intensity and prey at aquaculture and non-aquaculture areas. In addition, we also beach seined, and along the east coast of Vancouver Island to determine the incidence of microplastics in juvenile Chinook salmon and their nearshore environments. No significant differences were found between areas in the abundance, diets, condition or feeding intensity of juvenile Coho and Chinook. Chum had different prey and a higher condition and feeding intensity at aquaculture sites, suggesting that species such as Chum feeding on more benthic prey items have a higher probability of being impacted by shellfish aquaculture modifications and in this case we observed positive effects. Microplastic analysis showed juvenile Chinook salmon contained 1.15 1.41 (SD) microplastics per individual while water and sediment samples had 659.88 520.87 microplastics m-3 and 60.2 63.4 microplastics kg-1 dry weight, respectively. We found no differences in microplastic concentrations in juvenile Chinook and water samples among sites but observed significantly higher concentrations in sediment at our Deep Bay site compared to Nanaimo and Cowichan Bay. These differences may be due to site bathymetry and oceanographic differences facilitating settlement at the Deep Bay site and/or may be a result of differential plastic sources in the area including shellfish farming and a marina. Shellfish aquaculture had negligible or positive effects on juvenile salmon abundance, diet, condition and feeding intensity and Chinook microplastic concentrations were relatively low compared to literature values. Although fitness consequences and ecosystem-wide implications must be addressed in the future, it appears shellfish aquaculture and microplastics are not immediate threats to juvenile Pacific salmon along the east coast of Vancouver Island at this time. However, continued monitoring programs and larger-scale studies should be implemented as shoreline modification and plastic use continues to increase.

More Papers Like This

Article Tier 2

Human activity shapes microplastics and water quality in an endangered salmon habitat

AI summary Read the abstract

Researchers assessed microplastic contamination in a protected headwater stream supporting the endangered Formosan landlocked salmon, finding 1.0 to 3.3 particles per liter dominated by anthropogenic rayon fibers, with abundance positively linked to nutrient and ionic gradients reflecting upstream human land use.

Article Tier 2

Occurrence, bioaccumulation and ecological risk of aquaculture-derived microplastics in coastal waters

AI summary Read the abstract

Researchers reviewed microplastic contamination from aquaculture activities and found that fishing nets, foam buoys, and plastic packaging release large quantities of particles into coastal waters, with aquaculture-derived microplastics accounting for up to 99% of total microplastics at some sites. Cultured seafood consistently showed higher microplastic burdens than wild shellfish, highlighting aquaculture as a major but underestimated pollution source.

Article Tier 2

Microplastic Pollution in Shellfish Aquaculture: Occurrence, Impact, and Possible Remedies

AI summary Read the abstract

This review documents widespread microplastic contamination in shellfish aquaculture, detailing how MPs enter farming systems and cause toxicological harm, behavioral changes, growth suppression, and reproductive failure in commercially farmed shellfish. Because shellfish are filter feeders consumed whole by humans, MP accumulation in these species creates a direct and concentrated pathway for human ingestion.

Article Tier 2

Microplastic Impacts in Fisheries and Aquaculture

AI summary Read the abstract

Researchers reviewed a decade of evidence on microplastic uptake in commercially harvested fish and aquaculture species, assessing contamination levels, biological impacts, and the implications for food safety as seafood consumption continues to be a major human exposure pathway.

Article Tier 2

Microplastic Impacts in Fisheries and Aquaculture

AI summary Read the abstract

Researchers reviewed evidence that fish and seafood destined for human consumption are ingesting microplastics, documenting the breadth of contamination across commercially important species and what it means for the safety of seafood that billions of people eat regularly.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper