Petri Suuronen

ISCG

Commercial small-scale fisheries along the Baltic Sea coasts have declined over the years although these fisheries are viewed as important for coastal development and food security at the local, national, and EU levels. The viability and future of small-scale fisheries are severely challenged by problems caused by grey seals. The conflict, occurrin...

Recovery of many seal populations has intensified seal-fishery conflicts. Acoustic deterrent devices (ADDs), designed to deter seals while minimising collateral harm, provide a potential solution. We investigated feasibility of ADDs to protect a European whitefish (Coregonus lavaretus) fishery in the River Iijoki, Finland, which enters the Baltic S...

Mobile bottom contact gear such as trawls is widely considered to have the highest environmental impact of commonly used fishing gears, with concern about impact on benthic communities, bycatch, and carbon footprint frequently highlighted as much higher than other forms of fishing. As a result, the use of such gears has been banned or severely rest...

The rapid expansion of the global footprint of marine capture fisheries over recent decades, combined with the transition to synthetic and more durable materials used for fishing gear components, has resulted in increasingly problematic adverse ecological and socioeconomic effects from abandoned, lost and discarded fishing gear (ALDFG). Adverse imp...

We evaluated the effect of emptying techniques of a pontoon trap on mortality of Atlantic salmon on their spawning migration along the Finnish coast of the northern Baltic Sea by tagging and releasing fish from commercial trap nets. Two methods currently used, a traditional emptying chute and a lifting bag, were compared. The lifting bag has been d...

The survival and injuries of wild Atlantic salmon released by coastal fishers from pontoon traps was examined in the early summer of 2020 in the Gulf of Bothnia in the northern Baltic Sea. A total of 491 salmon caught with pontoon traps was tagged with dart tags. By the end of December 2020, a total of 62 tag recoveries (13%) were received. Sixty-t...

Trap fishing offers many potential benefits such as high catch quality and the possibility to release unwanted catch alive. The use of wild fish as a bait in trap fishing, however, can be troublesome and may involve sustainability concerns. There is a need for accessible and sustainable alternative attractant that is not based on marine resources w...

There has been increasing recognition of the need to address adverse ecological and socioeconomic effects of abandoned, lost and discarded fishing gear (ALDFG). This component of marine debris has been progressively problematic over recent decades with the rapid expansion of global fisheries’ footprint and effort, and the transition to synthetic an...

With the rapid growth of grey seal (Halichoerus grypus) population in the Baltic Sea, seal-induced catch losses have increased dramatically in coastal fisheries. There have been various attempts to mitigate these damages, such as modification of fishing gear, but solutions have proven inadequate. Promising research results have recently been obtain...

Reducing the capture of non-target species and juvenile fishes through a variety of gear modifications and bycatch reduction devices are presumed to provide long-term biological and socioeconomic benefits and improve the reputation of fisheries. The adoption of these technologies by fisheries, however, has been low compared to research and developm...

Bottom trawling is widespread globally and impacts seabed habitats. However, risks from trawling remain unquantified at large scales in most regions. We address these issues by synthesizing evidence on the impacts of different trawl-gear types, seabed recovery rates, and spatial distributions of trawling intensity in a quantitative indicator of bio...

Signal crayfish (Pacifastacus leniusculus) is a freshwater crayfish, originally from the west coast of North America. It is now widespread in Europe and it is listed as a harmful species in the list of invasive species of European Union concern. We tested the effect of LED lights in signal crayfish trapping in a large Finnish lake. Light attraction...

Trap fisheries can provide catches of high quality, and unwanted bycatch can be released with high survival. Light attraction could be an effective way of increasing trap catches, but research results are largely lacking. Experiments to test the effect of LED lights in trap‐net fishing were conducted in two Finnish lakes where fishing targeted Eura...

The eastern Baltic cod (Gadus morhua) stock is at a critically low level and recruitment of the western Baltic cod stock is at the lowest observed level in over 30 years. The EU (European Union) landing obligation was introduced in 2015 for cod and in 2017 for plaice (Pleuronectes platessa). Size selective codend designs have been used in the Balti...

Derelict abandoned, lost and discarded fishing gear have profound adverse effects. We assessed gear-specific relative risks from derelict gear to rank-order fishing methods based on: derelict gear production rates, gear quantity indicators of catch weight and area of fishing grounds, and adverse consequences from derelict gear. The latter accounted...

Bottom trawl fishing is a controversial activity. It yields about a quarter of the world's wild seafood, but also has impacts on the marine environment. Recent advances have quantified and improved understanding of large‐scale impacts of trawling on the seabed. However, such information needs to be coupled with distributions of benthic invertebrate...

Trawl fishing constitutes an important part of the marine fisheries sector in Southeast Asia. It provides livelihoods and food for millions of people in coastal communities as well as feed for the region’s growing aquaculture sector. Trawl fisheries suffer from a multitude of problems, including overcapacity, excessive fishing effort, poor profitab...

Bottom trawl fisheries are the most widespread source of anthropogenic physical disturbance to seabed habitats. Development of fisheries‐, conservation‐ and ecosystem‐based management strategies requires the selection of indicators of the impact of bottom trawling on the state of benthic biota. Many indicators have been proposed, but no rigorous te...

Bottom trawling accounts for almost one quarter of global fish landings but may also have significant and unwanted impacts on seabed habitats and biota. Management measures and voluntary industry actions can reduce these impacts, helping to meet sustainability objectives for fisheries, conservation and environmental management. These include change...

Accurate data on discards, the proportion of the catch that fishers do not retain, is necessary to achieve socioeconomically and ecologically sustainable fisheries. We review conventional and emerging approaches to monitor and manage discards. At-sea human observer programs currently produce the most accurate data on discards. Electronic monitoring...

Bycatch in fisheries can have profound effects on the abundance of species with relatively low resilience to increased mortality, can alter the evolutionary characteristics and concomitant fitness of affected populations through heritable trait-based selective removals, and can alter ecosystem functions, structure and services through food web trop...

A Third Assessment of Global Marine Fisheries Discards

Bottom trawling is the most widespread human activity directly affecting seabed habitats. Assessment and effective management of the effects of bottom trawling at the scale of fisheries requires an understanding of differences in sensitivity of biota to trawling. Responses to disturbance are expected to depend on the intrinsic rate of increase in p...

Significance We conducted a systematic, high-resolution analysis of bottom trawl fishing footprints for 24 regions on continental shelves and slopes of five continents and New Zealand. The proportion of seabed trawled varied >200-fold among regions (from 0.4 to 80.7% of area to a depth of 1,000 m). Within 18 regions, more than two-thirds of seabed...

Bottom-contact fishing gears are globally the most widespread anthropogenic sources of direct disturbance to the seabed and associated biota. Managing these fishing disturbances requires quantification of gear impacts on biota and the rate of recovery following disturbance. We undertook a systematic review and meta-analysis of 122 experiments on th...

Monitoring live and dead discarded catch contributes to effective fisheries management and ecological and socioeconomic sustainability. We determined contemporary rates and levels of discards in global tuna fisheries. An estimated 265,279 t (52,283-478,275 95% CI) is annually discarded by global tuna fisheries, composing about 5% of the weight of t...

Aim Trawling is the most widespread direct human disturbance on the seabed. Knowledge of the extent and consequences of this disturbance is limited because large‐scale distributions of seabed fauna are not well known. We map faunal distributions in the Australian Exclusive Economic Zone ( EEZ ) and quantify the proportion of their abundance that oc...

Bottom trawling is the most widespread human activity affecting seabed habitats. Here, we collate all available data for experimental and comparative studies of trawling impacts on whole communities of seabed macroinvertebrates on sedimentary habitats and develop widely applicable methods to estimate depletion and recovery rates of biota after traw...

Data required from fisheries monitoring programmes substantially expand as management authorities transition to implement elements of ecosystem-based fisheries management (EBFM). EBFM extends conventional approaches of managing single fishery effects on individual stocks of target species by taking into account the effects, within a defined ecosyst...

Impacts of bottom fishing, particularly trawling and dredging, on seabed ( benthic ) habitats are commonly perceived to pose serious environmental risks. Quantitative ecological risk assessment can be used to evaluate actual risks and to help guide the choice of management measures needed to meet sustainability objectives. We develop and apply a qu...

This document is the final report of the Symposium on Impacts of Fishing on the Environment arranged by the ICES-FAO Working Group on Fishing Technology and Fish Behaviour (WGFTFB) and held from 6 to 10 May 2013 in Bangkok, Thailand. The document was prepared by Mr Steve Eayrs (Gulf of Maine Research Institute, Maine, USA) and Mr Petri Suuronen (Fi...

(No abstract)

When synthetic non-biodegradable fishing nets are lost, abandoned or discarded at sea, they may continue to catch fish and other animals for a long period of time. This phenomenon is known as ‘ghost fishing’. Biodegradable fishing nets, on the other hand, are intended to degrade or decompose after a certain period of time under water and thereby lo...

The ecological and socioeconomic problems caused by abandoned, lost and discarded fishing gear (ALDFG) are increasingly of concern. Marine gillnets and trammel nets, which have relatively high ghost fishing potential, are globally important gear types. Used primarily by coastal, artisanal, small-scale fisheries worldwide, gillnet and trammel net fi...

Balanced harvesting (BH) has been proposed as an alternative to the paradigm of more selective fishing as practiced in most European and North American fisheries management. We examine options for the implementation of BH and evaluate the issues raised in such an implementation. Implementation is considered at the whole ecosystem level, in terms of...

Management and technical approaches that achieve a sustainable level of fish production while at the same time minimizing or limiting the wider ecological effects caused through fishing gear contact with the seabed might be considered to be ‘best practice’. To identify future knowledge-needs that would help to support a transition towards the adopt...

The concept of the Ecosystem Approach has entered the fishery harvesting discussions both from fishery perspectives (Reykjavik Declaration; FAO 2003 Annex to the Code of Conduct and from the principles of the Ecosystem Approach adopted by the CBD in 1995. Both perspectives establish the need to maintain ecosystem structure and functioning, whether...

Jigging with artificial lights (squid jigging) and deploying of large scale trap-net (also known as a set-net in Japan), are the major methods to capture Japanese common squid Todarodes pacificus in western Japan. Squid jigging is a highly selective fishing method. However, it consumes large amount of energy for steaming to the fishing ground and f...

Selective fishing might have practiced since fishing began as most fishing gears inherently select for species and size. Fueled by a desire to reduce bycatch and discards that are viewed as a waste of fisheries resource, the fishing industry are required to use the most selective gear that targets only certain species and sizes to meet the requirem...

Inland fisheries are an important source of food and livelihood. However, the socio-economic importance of inland fisheries is often undervalued and inadequately addressed in national and international policies for development. Furthermore, while irresponsible fishing can have serious consequences, there are also many outside threats to inland fish...

Cryptic, not readily detectable, components of fishing mortality are not routinely accounted for in fisheries management because of a lack of adequate data, and for some components, a lack of accurate estimation methods. Cryptic fishing mortalities can cause adverse ecological effects, are a source of wastage, reduce the sustainability of fishery r...

We examined the digestive tract contents of 63 Baltic grey seals (Halichoerus grypus) and 37 Baltic ringed seals (Phoca hispida botnica) collected during May to November in 2008 and 2009 in the northern part of the Bothnian Bay to assess the role of Atlantic salmon (Salmo salar) and sea trout (Salmo trutta) in the diet of seals. For grey seals the...

Fishing provides high quality seafood and creates employment and income for people worldwide. Most of the capture methods used for fishing are, however, heavily dependent on the use of fossil fuels. For many important fisheries their high consumption of fuel constitutes a major constraint to their economic viability but also represents a significan...

Canadian Journal of Fisheries and Aquatic Sciences, vol. 49, 2104 - 2117 A twin codend trawl was fished in the northern Baltic to study the size selectivity of square mesh and diamond mesh codends of 36-mm nominal mesh size. For each codend, 15 hauls were completed with a small mesh (20 mm) codend deployed on the other side of the trawl. The relati...

The Finnish coastal fishery of Atlantic salmon (Salmo salar) in the northern Baltic Sea is regulated using multi-annual, pre-fixed, opening dates of harvests that aim to enhance spawning escapement of early migrating wild salmon. Such an inflexible management regime does not set regulations that track varying run sizes of salmon. We introduce an ar...

Introduction Mortality of Discards and Escapees Assessment of Mortality Factors Causing Stress, Injury, and Mortality Measures to Improve Survival Concluding Remarks References

Much of the research that concerns the impacts of management measures in the eastern Baltic cod fishery has focused on fish stock rather than understanding fishermen's attitudes towards regulations. Hence, there is little information available on fishermen's responses although they are the ones whom the regulations affect most profoundly. This stud...

Seal-induced catch damages have increased dramatically in the coastal trap-net fishery in the Baltic Sea. Most damage is caused by the rapidly growing grey seal (Halichoerus grypus) population. These seal–fishery interactions require practical and sustainable solutions. A potential measure is capture of live seals using fishers’ commercial trap-net...

Abstract Return migration of Atlantic salmon, Salmo salar L., was studied in the Gulf of Bothnia, northern Baltic Sea, by a mark-recapture experiment and catch records from commercial trap-nets. Coastal salmon fishing is regulated by delayed opening of the fishery in consecutive regions based on the assumption that the wild fish migrate before rear...

The conference ‘Fish Stock Assessment Methods for Lakes and Reservoirs: Towards the True Picture of Fish Stock’ (FSAMLR) was held in September 2007 in Ceske Budejovice, Czech Republic. A total of 110 participants from 34 countries attended the meeting and 93 lectures were presented. Great advances were reported in fish surveys using hydroacoustics...

The mortality and stress responses (plasma cortisol concentration) of undersized (total length, LT, <370 mm) pike-perch Sander lucioperca caught as by-catch in a trawl fishery were assessed. The effects of three different holding methods on pike-perch caught by trawl were compared: (1) fish that were transferred to ambient-temperature water (15·0–2...

We explored the potential ecosystem effects of improved selectivity in the South Catalan Sea demersal trawl fishery. A calibrated food web model representing current conditions of the ecosystem and selectivity data from recent fishing experiments were used to perform temporal dynamic simulations. This enabled the evaluation of direct and indirect i...

The demersal multispecies trawl fishery in the western Mediterranean Sea has a poor selectivity; large numbers of juvenile fish are caught when using the legislated 40-mm diamond mesh cod end. The selectivity of a flexible sorting grid with 20-mm bar spacing (BS20) installed in front the conventional trawl cod end was investigated. The standard cov...

Suuronen, P., Tschernij, V., Jounela, P., Valentinsson, D., and Larsson, P-O. 2007. Factors affecting rule compiance with mesh size regulations in the Baltic cod trawl fishery. – ICES Journal of Marine Science, 64: 1603–1606. In this study, we evaluate the efficiency and applicability of a series of gear-based management measures, enforced since 19...

Bahamon, N., Sardà, F., and Suuronen, P. 2007. Potential benefits from improved selectivity in the northwest Mediterranean multispecies trawl fishery. – ICES Journal of Marine Science, 64: 757–760. The management scheme in the northwest Mediterranean multispecies demersal fishery is based largely on technical measures such as minimum mesh and landi...

Suuronen, P., and Sardà, F. 2007. The role of technical measures in European fisheries management and how to make them work better. – ICES Journal of Marine Science, 64: 751–756. Technical measures such as gear restrictions are commonly used in European fisheries management. Many of the measures are aimed primarily at protecting juveniles. Although...

In project NECESSITY (contract 501605) twenty three institutes and their respective sub-contractors were working together in two Task Groups, i.e. Nephrops and Cetaceans to develop alternative gear modifications and fishing tactics in collaboration with the fishing industry to reduce by-catches in the relevant Nephrops and pelagic fisheries, withou...

Commercial fishing trials with 40 mm diamond (DM40) and square (SM40) mesh codends made of 5 mm diameter knotted PE-netting were conducted in July 2005 on the continental shelf (∼100 m) and upper slope (∼400 m) of the Catalan Sea (NW Mediterranean) to assess the size selectivity of European hake (Merluccius merluccius), Norway lobster (Nephrops nor...

The major wild Atlantic salmon stocks in the Baltic Sea began to recover in the late 1990s. This recovery has been partly due to strict regulations in the Gulf of Bothnia that effectively prevent salmon fisheries during the peak migration. About half of the migrating salmon, however, are reared fish that could be harvested. We simulated a limited t...

We estimated the total size of the Atlantic salmon (Salmo salar) population complex (wild and cultured) in the Gulf of Bothnia, northern Baltic Sea, using a stratified mark-recapture method. In 2001 and 2002, 1970 salmon were captured by the commercial trapnet fishery and tagged with external arrow tags. A total of 349 tagged fish was later recaptu...

More than 50% of the world's total marine catch (approximately 81 million tonnes) is harvested using towed fishing gears (i.e. Danish seines, dredges and otter and beam trawls). As for all methods, the total fishing mortality of these gears comprises the reported (landed) and unreported catch and other unaccounted, collateral deaths due to (i) avoi...

Interactions between grey seal, Atlantic salmon, and harvest controls on the salmon fishery in the Gulf of Bothnia, northern Baltic Sea, were investigated for the period 1999-2003. We assessed the effects of seal-induced catch losses (fish damaged or eaten by seals in the fishing gears) and harvest restrictions (delayed sequential opening of the fi...

During the last decade, seal-induced catch and gear damage have increased dramatically in the coastal trap-net fishery in the northern Baltic Sea. Our trials show that it is possible to markedly reduce seal damage by appropriate gear modifications and by careful choice of netting material. Five trap-net modifications and two traditional traps (four...

Seal-induced damage in the traditional trap-net fishery increased dramatically during the 1990s in the northern Baltic Sea. Most damage is induced by a rapidly growing grey seal (Halichoerus grypus) population. We evaluated seal damage in the coastal trap-net fishery of the Gulf of Bothnia, where different gear constructions and netting materials a...