We describe an investigation into the challenges faced by fishing gear technologists inspiring the voluntary uptake of proven fishing gear by fishers, defined as fishing gear that has satisfied research objectives following field trials between fishers and fishing gear technologists. We applied a multifaceted approach to understand how the uptake rate of this fishing gear can be achieved based on the results of a 3-year ICES-FAO Working Group on Fishing Technology and Fish Behaviour (WGFTFB) topic group on change management in fisheries. This was supported by an online survey and interview of WGFTFB members, comprising mainly of fishing gear technologists and researchers from Europe and North America, and a review of projects in the US Northwest Atlantic to evaluate the performance of fishing gear in close collaboration with fishers. We found that widespread voluntary uptake of proven fishing gear by fishers is rare, and usually takes place over many years if at all. The uptake of this gear was more likely occur in the face of perceived financial benefit or impending regulation, although financial benefit was not always sufficient inducement for fishers change their gear. The effectiveness of outreach programmes to inspire the uptake of this gear was also found to be questionable, and the efficacy of incentives was limited and inconsistent, even if the informational deficit of fishers was low. Few WGFTFB members were found to use change management models such as that by Kotter, and they relied mainly on informal, ad hoc approaches to inspire the uptake of proven fishing gear. Based on our findings we posit a need to (i) examine our assumptions about the behaviour of fishers, (ii) augment communication of the results of fishing gear research, (iii) focus on emotions to overcome motivational deficits, and (iv) consider how the application of change management models can improve the ability of fishing gear technologists to inspire the uptake of proven fishing gear by fishers.

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 the patterns of removal for all species, both commercial and bycatch. We suggest that a “laissez-faire” approach analogous to the African lakes where BH was first observed is inappropriate in managed developed world fisheries. We consider two further approaches: focusing on either the species caught or on the sizes of animal alone. We find that aiming to harvest all species with an exploitation rate appropriate to their productivity would require a degree of micro-management that is probably unachievable, with all captured species “choking” the fishery in sequence. The size-based approach works with an exploitation rate appropriate to the productivity at size, with no consideration of the species involved. This might superficially be easier to implement, as management would involve a limited number of size classes only. However, problems may arise due to the likely faster capture of the more easily catchable fish, and also likely targeting of the more valuable species within a size class. We identify a possible third option of “broad brush” métier-based management that may resolve some of these problems. Other issues include the management of protected, endangered, and threatened species (including mammals, reptiles, and birds), the management of already severely depleted stocks, and the capture of benthic invertebrates.

We conducted laboratory experiments in the summers of 1986 and 1987 to examine the effects of Daphnia pulex body size and ration level on growth of age-0 yellow perch Perca flavescens. Daphnia pulex rations were set at 25 and 40% of yellow perch dry weight. Specific growth rate tended to be higher for smaller fish and decreased with fish size at both ration levels. For the 25% ration, the highest growth rates, 0.023 to 0.024 g/d, were observed when yellow perch were fed meals of D. pulex between 1.4 and 1.8 mm long; growth declined for prey sizes outside this size range. For the 40% ration, no relationship was found between body length of D. pulex and specific growth rate; the mean specific growth rate for the 40% ration was the same as the peak rate for the 25% ration. Multiple-regression analysis was used to examine the dependence of specific growth rate of yellow perch on initial fish length, prey size, and temperature. For the 25% ration, prey size and the square of prey size were the only va...

Underwater video recordings in the mouth of a squid trawl were used to evaluate the effectiveness of a trawl configured with drop-chain groundgear to catch longfin inshore squid (Doryteuthis pealeii) and reduce bycatch of finfish in the Nantucket Sound squid fishery off Cape Cod, Massachusetts, USA. Entrance through the trawl mouth or escape underneath the fishing line and between drop chains was quantified for targeted squid, and two major bycatch species, summer flounder (Paralichthys dentatus) and skates (family Rajidae). Additionally, contact and impingement between animals and groundgear were also quantified. Fish and squid swimming behaviours, positions, orientations, and time in the trawl mouth were quantified and related to capture or escape at the trawl mouth. Squid entered the trawl singly and in schools, and no squid were observed escaping under the fishing line. Most squid entered the trawl in the upper portion of the trawl mouth; mantle orientated away from the trawl and swimming in the same direction, and were gradually overtaken, not actively attempting to escape. Summer flounder and skates were observed to remain on or near the seabed, orientated, and swimming in the same direction as the approaching trawl. The majority (60.5%) of summer flounder entered the trawl above the fishing line. Summer flounder that changed their orientation and turned 180° were significantly more likely to enter the trawl (p < 0.05). Most skates (89.7%) avoided trawl entrance and escaped under the fishing line. Neither squid nor summer flounder were observed to make contact or become impinged to the groundgear; however, 35.4% of skates had substantial contact with groundgear, with 12.3% becoming impinged. Video analysis results showed that the drop-chain trawl is effective at retaining targeted squid while allowing skates to escape. However, it is ineffective at avoiding the capture of summer flounder.