Could fish aggregation at ocean aquaculture augment wild populations and local fisheries?

The global population consumes more seafood from aquaculture today than from capture fisheries and although the aquaculture industry continues to grow, both seafood sectors will continue to be important to the global food supply into the future. As farming continues to expand into ocean systems, understanding how wild populations and fisheries will interact with farms will be increasingly important to informing sustainable ocean planning and management. Using a spatially explicit population and fishing model we simulate several impacts from ocean aquaculture (i.e., aggregation, protection from fishing, and impacts on fitness) to evaluate the mechanisms underlying interactions between aquaculture, wild populations and fisheries. We find that aggregation of species to farms can increase the benefits of protection from fishing that a farm provides and can have greater impacts on more mobile species. Splitting total farm area into smaller farms can benefit fishery catches, whereas larger farms can provide greater ecological benefits through conservation of wild populations. Our results provide clear lessons on how to design and co-manage expanding ocean aquaculture along with wild capture ecosystem management to benefit fisheries or conservation objectives.

Conventional and nano-copper pesticides are equally toxic to the estuarine amphipod Leptocheirus plumulosus

Modern nano-engineered pesticides have great promise for agriculture due to their extended, low dose release profiles that are intended to increase effectiveness but reduce environmental harm. Whether nanopesticides, including copper (Cu) formulations, cause reduced levels of toxicity to non-target aquatic organisms is unclear but important to assess. Predicting how aquatic species respond to incidental exposure to Cu-based nanopesticides is challenging because of the expected very low concentrations in the environment, and the two forms of exposure that may occur, namely to Cu ions and Cu nanoparticles. We conducted Cu speciation, tissue uptake, and 7-day toxicity laboratory experiments to test how a model estuarine organism, the amphipod Leptocheirus plumulosus, responded to two popular Cu-based nanopesticides, CuPRO and Kocide, and conventional CuCl₂. Exposure concentrations ranged from 0 to 2.5 ppm, which were similar to those found in estuarine water located downstream of agricultural fields. Cu dissolution rates were much slower for the nanopesticides than the ionic formula, and Cu body burden in amphipods increased approximately linearly with the nominal exposure concentration. Amphipod survival declined in a normal dose-response manner with no difference among Cu formulations. Growth and movement rates after 7 days revealed no difference among exposure levels when analyzed with conventional statistical methods. By contrast, analysis of respiration rates, inferred from biomass measurements, with a bioenergetic toxicodynamic model indicated potential for population-level effects of exposure to very low-levels of the two nanopesticides, as well as the control contaminant CuCl₂. Our results indicate that toxicity assessment of environmental trace pollutant concentrations may go undetected with traditional ecotoxicological tests. We present a process integrating toxicity test results and toxicodynamic modeling that can improve our capacity to detect and predict environmental impacts of very low levels of nanomaterials released into the environment.

Environmental Benefits of Novel Nonhuman Food Inputs to Salmon Feeds

Global population growth and changing diets increase the importance, and challenges, of reducing the environmental impacts of food production. Farmed seafood is a relatively efficient way to produce protein and has already overtaken wild fisheries. The use of protein-rich food crops, such as soy, instead of fishmeal in aquaculture feed diverts these important protein sources away from direct human consumption and creates new environmental challenges. Single cell proteins (SCPs), including bacteria and yeast, have recently emerged as replacements for plant-based proteins in salmon feeds. Attributional life cycle assessment is used to compare salmon feeds based on protein from soy, methanotrophic bacteria, and yeast ingredients. All ingredients are modeled at the industrial production scale and compared based on seven resource use and emissions indicators. Yeast protein concentrate showed drastically lower impacts in all categories compared to soy protein concentrate. Bacteria meal also had lower impacts than soy protein concentrate for five of the seven indicators. When these target meals were incorporated into complete feeds the relative trends remain fairly constant, but benefits of the novel ingredients are dampened by high impacts from the nontarget ingredients. Particularly, primary production requirements (PPR) are about equal and constant across all feeds for both analyses since PPR was driven by fishmeal and oil. The bacteria-based feed has the highest climate change impacts due to the use of methane to feed the bacteria who then release carbon dioxide. Overall, the results of this study suggest that incorporating SCP ingredients into salmon feeds can help reduce the environmental impacts of salmon production. Continued improvements in SCP production would further increase the sustainability of salmon farming.

A funder-imposed data publication requirement seldom inspired data sharing

Growth of the open science movement has drawn significant attention to data sharing and availability across the scientific community. In this study, we tested the ability to recover data collected under a particular funder-imposed requirement of public availability. We assessed overall data recovery success, tested whether characteristics of the data or data creator were indicators of recovery success, and identified hurdles to data recovery. Overall the majority of data were not recovered (26% recovery of 315 data projects), a similar result to journal-driven efforts to recover data. Field of research was the most important indicator of recovery success, but neither home agency sector nor age of data were determinants of recovery. While we did not find a relationship between recovery of data and age of data, age did predict whether we could find contact information for the grantee. The main hurdles to data recovery included those associated with communication with the researcher; loss of contact with the data creator accounted for half (50%) of unrecoverable datasets, and unavailability of contact information accounted for 35% of unrecoverable datasets. Overall, our results suggest that funding agencies and journals face similar challenges to enforcement of data requirements. We advocate that funding agencies could improve the availability of the data they fund by dedicating more resources to enforcing compliance with data requirements, providing data-sharing tools and technical support to awardees, and administering stricter consequences for those who ignore data sharing preconditions.