Search results for "Management."
showing 10 items of 16365 documents
Jellyfish Impacts on Marine Aquaculture and Fisheries
2020
Over the last 50 years, there has been an increased frequency and severity of negative impacts affecting marine fishery and aquaculture sectors, which claimed significant economic losses due to the interference of stinging gelatinous organisms with daily operational activities. Nevertheless, original scientific information on jellyfish-related incidents, their consequences, and potential preventative and mitigation countermeasures is limited and scattered across gray literature, governmental technical reports, and communication media. A literature scan searching for records of any interactions between jellyfish and the marine fishery/aquaculture sectors were carried out. Out of 553 papers, …
LTSER platforms as a place-based transdisciplinary research infrastructure: learning landscape approach through evaluation
2019
Context: Place-based transdisciplinary research involves multiple academic disciplines and non-academic actors. Long-Term Socio-Ecological Research (LTSER) platform is one concept with ~ 80 initiatives globally. Objectives: As an exercise in learning through evaluation we audited (1) the siting, construction and maintenance of individual LTSER platforms, and (2) them as a distributed infrastructure for place-based transdisciplinary research with focus on the European continent. Methods: First, we defined a normative model for ideal performance at both platform and network levels. Second, four surveys were sent out to the 67 self-reported LTSER platforms officially listed at the end of 2016.…
Harvest‐induced evolution and effective population size
2016
Much has been written about fishery-induced evolution (FIE) in exploited species, but relatively little attention has been paid to the consequences for one of the most important parameters in evolutionary biology-effective population size (N-e). We use a combination of simulations of Atlantic cod populations experiencing harvest, artificial manipulation of cod life tables, and analytical methods to explore how adding harvest to natural mortality affects N-e, census size (N), and the ratio N-e/N. We show that harvest-mediated reductions in N-e are due entirely to reductions in recruitment, because increasing adult mortality actually increases the N-e/N ratio. This means that proportional red…
PERSPECTIVE: Underutilized resources for studying the evolution of invasive species during their introduction, establishment, and lag phases
2010
The early phases of biological invasions are poorly understood. In particular, during the introduction, establishment, and possible lag phases, it is unclear to what extent evolution must take place for an introduced species to transition from established to expanding. In this study, we highlight three disparate data sources that can provide insights into evolutionary processes associated with invasion success: biological control organisms, horticultural introductions, and natural history collections. All three data sources potentially provide introduction dates, information about source populations, and genetic and morphological samples at different time points along the invasion trajector…
The consequences of size-selective fishing mortality for larval production and sustainable yield in species with obligate male care
2020
AbstractSize-based harvest limits or gear regulations are often used to manage fishing mortality and ensure the spawning biomass of females is sufficiently protected. Yet, management interactions with species’ mating systems that affect fishery sustainability and yield are rarely considered. For species with obligate male care, it is possible that size-specific harvest of males will decrease larval production. In order to examine how size-based management practices interact with mating systems, we modeled fisheries of two species with obligate care of nests, corkwing wrasse (Symphodus melops, Labridae) and lingcod (Ophiodon elongatus, Hexigrammidae) under two management scenarios, a minimum…
Windthrow in streamside key habitats: Effects of buffer strip width and selective logging
2020
Abstract Streamside forests are preserved from clear-cut logging in production forests and protected with uncut buffer strips in many countries. However, buffer strips often remain narrow due to economic reasons and, therefore, provide weak protection against adverse edge effects of clear-cuts and are vulnerable to windthrow. Selective logging of buffer strips is sometimes allowed to reduce their costs, but the decreased tree density may expose the buffer to higher occurrence of windthrow. We used a replicated two-factor experiment to assess the effects of buffer width (15 m or 30 m) and selective logging (0% or 30% of the basal area removed) on the risk of windthrow in boreal streamside fo…
Four Perspectives of Applied Sustainability: Research Implications and Possible Integrations
2017
How is applied sustainability being understood and implemented in academics’ and practitioners’ circles? Participants to the workshop “Sustainability Performance Assessment” within the ICCSA 2017 conference are confronted with this overarching question, which they address from their specific backgrounds and theoretical standpoints.
The arthropod community of boreal Norway spruce forests responds variably to stump harvesting
2016
Forest fuel harvesting increases the need to collect not just logging residues but also tree stumps from harvested stands. This biomass removal has raised concern over forest biodiversity. Here, the effects of stump harvesting on spiders, ants, harvestmen, ground beetles and epiedaphic springtails occupying boreal Norway spruce (Picea abies) forest floor were studied two and five years after harvesting by comparing pitfall trap samples from clear-cut sites with and without subsequent stump harvesting and from unharvested mature forests in central Finland. At harvested sites, traps were placed both on intact and exposed mineral soil surface. Open-habitat and generalist ground beetles benefit…
Effectiveness of European Atlanto-Mediterranean MPAs: Do they accomplish the expected effects on populations, communities and ecosystems?
2008
The success of MPAs in conserving fishing resources and protecting marine biodiversity relies strongly on how well they meet their planned (or implicit) management goals. From a review of empirical studies aiming at assessing the ecological effects of Mediterranean and Macaronesian MPAs, we conclude that establishing an MPA is successful for (i) increasing the abundance/biomass, (ii) increasing the proportion of larger/older individuals, and (iii) enhancing the fecundity of commercially harvested populations; also, MPAs demonstrated to be effective for (iv) augmenting local fishery yields through biomass exportation from the protected area, and (v) inducing shifts in fish assemblage structu…
Identifying small pelagic Mediterranean fish schools from acoustic and environmental data using optimized artificial neural networks
2019
Abstract The Common Fisheries Policy of the European Union aims to exploit fish stocks at a level of Maximum Sustainable Yield by 2020 at the latest. At the Mediterranean level, the General Fisheries Commission for the Mediterranean (GFCM) has highlighted the importance of reversing the observed declining trend of fish stocks. In this complex context, it is important to obtain reliable biomass estimates to support scientifically sound advice for sustainable management of marine resources. This paper presents a machine learning methodology for the classification of pelagic species schools from acoustic and environmental data. In particular, the methodology was tuned for the recognition of an…