Perch length and age at catch, Catch Per Unit Effort of fish species, three-spined stickleback densities and temperature along the Swedish Baltic Sea coast (2002-2023)

These datasets contain data on 1) perch (Perca fluviatilis) total length and age at catch of individual fish, 2) Catch Per Unit Effort (CPUE) of perch and other fish species and average annual water temperature, 3) three-spined stickleback (Gasterosteus aculeatus) estimated densities, and 4) distance from the open sea of several locations spread along the Swedish Baltic Sea coast. Data in (1) and (2) were retrieved from the Swedish national database for coastal fish monitoring (slu.se/kul) [2025-05-15] and come from fish monitoring surveys that are conducted between mid-July and late August, using multi-mesh gillnets. Average annual water temperatures were calculated from daily mean sea surface temperatures from satellite data (E.U. Copernicus Baltic Sea L4 dataset (https://doi.org/10.48670/moi-00156) [2025-05-15]). Three-spined stickleback densities (3) were estimated following the approach outlined in Olin et al. (Nature Communications 2024) using data from the Baltic International Acoustic Survey, which runs annually in October and combines hydroacoustic data with trawl hauls to estimate densities. Distance from the open sea (4) was calculated in GIS environment (ArcGIS Pro 2.4, ESRI 2019) as the shortest water distance from the location to the baseline (a line tracing the outermost islands in the archipelago). Column headers and explanation: Data (1) year: year of fish data collection catch date: date of fish data collection species: common names of species, here only one level: Abborre = European perch sub.location: location name of data collection long: longitude of location lat: latitude of location total_length: total length (mm) of individual fish, measured from head to tail sex: sex, levels: Hona = female, Hane = male, Båda kön = both sex, Obestämd = unknow age: age (year-old). Data (2) sub.location: location name of data collection year: year of fish data collection Art: common names of species, levels: _ingen fångst = no species caught Abborre = European perch (Perca fluviatilis) Ål = European eel (Anguilla anguilla) Bergsimpa = Alpine bullhead (Cottus poecilopus) Björkna = white bream (Blicca bjoerkna) Braxen = bream (Abramis brama) Ejder = eider (Somateria mollissima) Gädda = pike (Esox lucius) Gärs = ruffe (Gymnocephalus cernuus) Gös = pike-perch (Sander lucioperca) Gråsej = pollack (Pollachius virens) Harr = grayling (Thymallus thymallus) Hornsimpa = fourhorn sculpin (Myoxocephalus quadricornis) Id = ide (Leuciscus idus) Knipa = common Goldeneye (Bucephala clangula) Kusttobis = lesser sandeel (Ammodytes tobianus) Lake = European burbot (Lota lota) Lax = salmon (Salmo salar) Löja = bleak (Alburnus alburnus) Makrill = mackerel (Scomber scombrus) Mindre havsnål = straightnose pipefish (Nerophis ophidion) Mindre kantnål = lesser pipefish (Syngnathus rostellatus) Mört = roach (Rutilus rutilus) Nors = smelt (Osmerus eperlanus) Okänd = unknown Öring = brown trout (Salmo trutta) Oxsimpa = long-spined bullhead (Taurulus bubalis) Piggvar = turbo (Psetta maxima) Regnbåge = rainbow trout (Oncorhynchus mykiss) Röding = Artic char (Salvelinus alpinus) Rödspätta = European plaice (Pleuronectes platessa) Rötsimpa = shorthorn sculpin (Myoxocephalus scorpius) Ruda = crucian carp (Carassius carassius) Sarv = rudd (Scardinius erythrophthalmus) Sik = whitefish (Coregonus lavaretus) Siklöja = vendace (Coregonus albula) Sill/Strömming = Baltic herring (Clupea harengus) Sjöorre = common scoter (Melanitta nigra) Skarpsill = sprat (Sprattus sprattus) Skrubbskädda = flounder (Platichthys flesus) Staksill = twait shad (Alosa fallax) Stäm = common dace (Leuciscus leuciscus) Storskrake = goosander (Mergus merganser) Storspigg = threespined stickleback (Gasterosteus aculeatus) Sutare = tench (Tinca tinca) Svart smörbult = black goby (Gobius niger) Svärta = velvet scoter (Melanitta fusca) Svartmunnad smörbult = round goby (Neogobius melanostomus) Tånglake = eelpout (Zoarces viviparus) Tångsnälla = broadnosed pipefish (Syngnathus typhle) Tejstefisk = rock gunnel (Pholis gunnellus) Tobiskung = great sandeel (Hyperoplus lanceolatus) Torsk = Atlantic cod (Gadus morhua) Tunga = common sole (Solea solea) Vigg = tufted duck (Aythya fuligula) Vimma = vimba bream (Abramis vimba) Vitling = whiting (Merlangius merlangus) length_group: total length of fish, measured from head to tail, rounded to the nearest cm avg_year_temp: average annual water temperature (degrees Celsius) CPUE: Catch Per Unit Effort for species, length group and sampling occasion. Data (3) sub.location: location name of data collection gear: numeric code indicating different gillnet stations in the location year: year of fish data collection BIASmean: estimated stickleback densities (number/squared meter) Data (4) sub.location: location name of data collection distance: distance (m) from the open sea of location gear: numeric code indicating different gillnet stations in the location