Northwest Newfoundland (DFO Salmon Fishing Area 14A), 7. We thank everyone that worked with the Swedish Carlin tagging programme and especially the staff at the former Swedish Salmon Research Institute for maintaining the dataset, to everyone that has reported captures of tagged salmon. Parr - Edge of adipose fin clear, without dark border. Nevertheless, according to Torniainen et al.

Breeding males develop a hooked jaw in the fall and can be very dark. Also, hatchery practices (e.g., size at release) could differ among our study populations; these have been shown to affect the feeding distribution of Finnish Baltic salmon populations (Jutila et al., 2003, Kallio‐Nyberg et al., 2011, 2015, Salminen et al., 1994) and the time spent at sea before returning to spawn (Kallio‐Nyberg et al., 2011, Orell et al., 2018). We also demonstrate that the populations differ in how variable their distributions at sea are, both between smolt year classes and among individuals within smolt year classes. To date, the annual numbers of adult sea-run salmon that successfully return to the river have ranged between 40 and 530 fish. An alternative is to use fisheries independent methods, such as stable‐isotope analyses from tissue samples of returning spawners (Dempson et al., 2010, MacKenzie et al., 2012, Torniainen et al., 2013). Annual stockings of surplus broodstock (2- to 18-pound hatchery-bred adults that are no longer viable for breeding) have created popular trophy fisheries in two rivers. Most salmon migrate to the southern Baltic Sea for feeding, but the extent of this southward migration varies both with origin of population and body size.
Anal rays 7-11. Similar to our findings, previous studies on the distribution of salmon at sea originating from Finnish rivers have shown that different salmon populations can feed in different areas of the Baltic Sea (Kallio‐Nyberg et al., 1999, Kallio‐Nyberg & Ikonen, 1992, Torniainen et al., 2013, 2017). Atlantic salmon make spawning runs up major rivers in North America from Quebec to Connecticut and in Europe from the Arctic Circle to Portugal. Knowledge on spatial distribution patterns is particularly important for anadromous species, where population dynamics is a consequence of the performance of individuals in both rivers and oceans (Chaput, 2012, Jensen et al., 2018, Moore et al., 2014). Any queries (other than missing content) should be directed to the corresponding author for the article. If a tagged individual is recaptured, the catcher is instructed to return the tag together with date, length, mass, type of fishing (recreational, commercial, brood stock or scientific), recapture location together with any additional comments. In the Baltic Sea, offshore mixed‐stock sea fisheries were long the dominant type of fisheries targeting Baltic salmon, but during the recent decades offshore fisheries have decreased (ICES, 2018, Karlsson & Karlström, 1994).

Interestingly, the most northerly originating populations reached the southern feeding grounds of the Baltic Sea first (at smallest size). Note reddish spots. Young fish in streams (parr and smolts) typically 3 to 8 inches, rarely to 12 inches. The differences between populations in mean latitudinal distribution decreased in the larger size classes (> 30–50 cm), but still also for these size classes, salmon from Ljusnan, Dalälven and Ljungan were caught mostly to the north.
Northeast Newfoundland (DFO Salmon Fishing Areas 3, 4, 5, 6, 7, 8), 4. Each recaptured salmon with information about the recapture location has been given a corresponding recapture zone according to a specific map (Supporting Information Figure S3) when entered into the database. South Newfoundland (DFO Salmon Fishing Areas 9, 10, 11, 12), 5. Hartford, CT. In 1967, a major restoration effort was initiated by state and federal fisheries agencies to restore the Connecticut River population. observed size 36 inches. Inner St. Lawrence Population (Quebec salmon zones Q4, Q5, Q6), 12. Distribution. For all analyses, the smallest size‐class, 10–30 cm, was excluded as these recaptures are governed by the location of each populations' river and not by the distribution of individuals feeding at sea (Figure 1 and Supporting Information Figure S4). (2013), assessing population‐specific distribution based on recaptures of individual salmon at sea provides similar results on a coarse spatial scale (feeding in either the northern or southern Baltic Sea) as retrospective distribution analyses using stable isotopes, collected from returning adults caught prior to spawning in their natal river. The largest size‐class, 110–130 cm, was excluded in all statistical analyses due to insufficient sample sizes to compare distribution among populations (Figure 1 and Supporting Information Figure S4). Few spots if any on tail, adipose or dorsal fins. Atlantic salmon culture began in the 19th century in the UK in freshwater as a means of stocking waters with parr in order to enhance wild returns for anglers. reported size 4.9 feet.

Atlantic Salmon Care. Nowadays, Baltic salmon are mainly exploited by commercial and recreational coastal and river fisheries (ICES, 2018). Adults - Similar to brown trout. This five decade long stability of observed distributions suggests population‐specific distribution differences hold over time. Habits. Sea cage culture was first used in the 1960s in Norway to raise Atlantic salmon to marketable size. Until 1999, the Swedish Salmon Research Institute managed the database containing all releases and recaptures of tagged individuals, after which the hydropower companies have managed the database. Working off-campus? We show strong population and size‐specific differences in distribution at sea, varying between year classes and between individuals within year classes.

The information on population‐specific distribution patterns provided herein is therefore important for implementation of population‐specific assessment and management of Baltic salmon also at sea. However, the latitudinal extent of this southward migration differed between populations (ANOVA, F1,9 = 33.642, P < 0.001) and size‐classes (ANOVA, F1,3 = 369.008, P < 0.001). Comparison of female (top) and male (bottom) hatchery-raised Atlantic salmon.

Mouth smaller than other trouts, jaw extends only to or slightly past the posterior margin of eye.

As we only compare recaptures of equally sized individuals for the same time period at sea, we argue that the population‐specific distribution differences found in our study are caused by differences in the spatial distribution between study populations and not by spatial differences in catchabilities due to population characteristics (e.g., any morphological differences making individuals from some populations more likely to be caught in specific areas of the Baltic Sea compared with others). Table 1 and Supporting Information Figure S7) suggests that local adaptation may play a role in the extent populations alter their distribution in response to environmental drivers.

Management of anadromous fish may require actions targeting individuals in both habitats (Allen & Singh, 2016). Still, the fact that we found population‐specific patterns of distribution variation among populations that did not significantly differ in smolt release size (cf. Thus, we argue that our results are important to consider in the future development of Baltic salmon assessment and management as salmon from different populations evidently experience different local environmental conditions and exploitation rates at sea.