- "Since 2009, all EU member states are obligated to evaluate recreational catches of Atlantic cod, European eel (Anguilla anguilla), Atlantic salmon (Salmo salar), European sea bass, and Atlantic bluefin tuna (Thunnus thynnus) in relevant regions."
- "Although not further specified, the Commission regulation instructs member states to collect data to estimate marine recreational catches... commonly defined as harvested and released fish... However, while catch-and-release (C&R) practices have been thoroughly studied in marine and freshwater recreational fisheries in the USA, Canada and Australia, and for a few freshwater fisheries in Europe..., only very few peer-reviewed publications exist on C&R practices in European marine recreational fisheries (e.g. Alo´s, 2008; Alo´s et al., 2009a, 2009b; Veiga et al., 2011; Ferteret al., 2013; Weltersbach and Strehlow, 2013)."
EAA comment: We have taken a closer look at four of the six papers mentioned above:
1) - Alo´s et al., 2009a:
“Influence of anatomical hooking depth, capture depth, and venting on mortality of painted comber (Serranus scriba) released by recreational anglers".ICES Journal of Marine Science, 65: 1620–1625.
Page 1: “Immediate (4–5 h) and delayed (10 d) hooking mortality for released fish kept in tanks was evaluated for painted comber (Serranus scriba) taken by the recreational fishery of the Balearic Islands (western Mediterranean). Results showed low rates of immediate (10.8%) and delayed (3.3%) hooking mortality, a total mortality of 14.1%. (..) Therefore, the results confirm that a practice of catch-and-release (voluntary or mandatory) for S. scriba needs to be promoted among recreational anglers.”
2) - Alo´s, J., Palmer, M., and Grau, A. M. 2009b: “
Mortality of Diplodus annularis and Lithognathus mormyrus released by recreational anglers: implications for recreational fisheries management.”
Fisheries Management and Ecology, 16: 298 –305
Cutting from the abstract:
“The circumstances of the catch, such as capture depth, water temperature, fish size, hook type, hook location, bleeding, unhooking time and cutting the hook line were tested with a logistic regression model. Diplodus annularis experienced moderate rates of mortality (15%), (..) By contrast, L. mormyrus exhibited higher mortality rates (33%) with over 90% of the catch under the minimum legal size. Deep-hooking was the strongest predictor of mortality. When circle hooks were used, or if the line was cut when the fish were deep-hooked, mortality was considerably reduced. Strategies, such as promoting the use of more selective gears that reduce the capture of undersized fish and implementing gentler release techniques, should be considered in managing these species.”
3) - Veiga, P., Goncalves, J. and Erzini, K. 2011: “
Short-term hooking mortality of three marine fish species (Sparidae) caught by recreational angling in the south Portugal.”
Fisheries Research, 108: 58 –64
Cutting from the abstract:
“Short-term hooking mortality was evaluated for three sparid species [Diplodus vulgaris(Geoffroy Saint-Hilaire), Sparus aurata L. and Spondyliosoma cantharus (L.)] in the Algarve, south Portugal. Fishes were caught from the shore during October 2009 at a fish farm reservoir (Ria Formosa), using three different hook sizes. The relationships between hooking mortality and seven independent variables were analyzed using logistic regression models. In all, 384 fishes representing the three target species were caught during the angling sessions. (..) Mortalities ranged between 0% for D. vulgaris and 12% for S. aurata (S. cantharus, 3%). Our results support the current mandatory practices of releasing undersized fish for the studied species, given the low post-release mortality rates observed.”
4) - Weltersbach and Strehlow, 2013; Weltersbach, M. S., and Strehlow, H. V. 2013. “Dead or alive – estimating post-release mortality of Atlantic cod in the recreational fishery."
ICES Journal of Marine Science.
Cutting from the abstract:
“This study investigates (i) the post-release mortality of undersized cod, (ii) potential factors affecting mortality, and (iii) consequences of the catch-and-release process on cod. During four experimental trials, western Baltic Sea cod were angled from a charter vessel and thereafter observed together with control fish in netpens for 10 d at holding temperatures between 6.2 and 19.88C. Adjusted mortality rates for angled cod ranged from 0.0–27.3% (overall mean 11.2%).”
Cuttings from the text: “Discussion – Mortality: The post-release mortality rate (adjusted for handling and caging effects) for angled cod ranged from 0.0 –27.3% (overall mean 11.2%). This overall mean mortality rate was close to the average release mortality rate of 18% calculated by Bartholomew and Bohnsack (2005), who carried out a meta-analysis of 274 catch-and-release mortality studies.”… Conclusions and implications: This study can be considered a first step in closing the existing scientific gap in investigating possible post-release mortalities and the consequences of catch-and-release on cod in the recreational fishery. Our findings suggest that a substantial amount of recreationally released cod survive and thus cannot be classified as removals from the western Baltic cod stock. However, the present post-release mortality rates should only serve as first estimations. The results have to be viewed with great caution on a population/stock level, as post-release mortality estimates derived from containment experiments cannot accurately predict recreational fishing mortality of a population in its natural environment.”
Case 3:
It is said on page 97:
1) - “Striped bass are very similar to European sea bass in terms of morphology, habitats and angling methods.”
EAA comment: That is not entirely accurate. Striped bass is an anadromous fish - migrates between sea- and freshwaters. Spawning takes place in freshwater. European sea bass is a marine fish, which spawns at sea.
2) - “The US National Marine Fisheries Service has in the past used an average hooking mortality of 9% for striped bass, estimated by Diodati and Richards (1996).”
EAA comment: The 9% mortality is the result from an experiment carried out in a saltwater pond with an average depth of approximately 3 m and surface water temperature ranging from 15 to 28°C. The paper is
here. It is important to make the distinction between saltwater and freshwater conditions, when doing experiments with striped bass, as: "
Predicted as well as observed mortality for the entire experimental group was 9% which is generally much lower than reported in striped bass hooking mortality studies conducted in freshwater". The experiment mimic bass angling under sea water conditions. It was concluded, that: “
Mean predicted mortality was 26% for the worst set of conditions, 9% for the intermediate set, and 3% for the best set (Table 4).”)
We find it fair to say that - everything considered - the experimental setup doesn't mimic exactly European sea angling under natural conditions e.g. the water temperatures seem above what would be normal for Northern European sea bass. So, even 9% is a fairly low mortality rate we would expect a release mortality rate for Northern sea bass to be below 9%.
3) – “A literature review of hooking mortality for a range of species compiled by the Massachusetts Division of Marine Fisheries included a total of 40 different experiments by 16 different authors where striped bass hooking mortality was estimated over two or more days (Gary A. Nelson, Massachusetts Division of Marine Fisheries, pers. comm.) The mean hooking mortality rate was 0.19 (standard deviation 0.19)”
EAA comment: We haven't looked into this as yet but we find it hard to believe that 40 different striped bass experiments would show a mean hooking mortality rate of 0.19. We would like to know more about these experiments and papers before we say more about that. We also find it confusing that everything said above is from a chapter (page 97) titled "Hooking mortality, and mortality of discarded bass from commercial vessels". We wonder if the 40 experiments are all genuine recreational angling experiements or include commercial line fishing as well? In any case, conclusions from experiments with striped bass angling in freshwaters, or fresh- and seawaters, should be moderated to show only results for seawater angling before making any comparison with European sea bass angling.
In the USA, the Atlantic States Marine Fisheries Commission currently applies an
8% mortality rate for striped bass caught and released by recreational anglers in saltwater ecosystems.