| 1. |
- Bergström, Ulf, et al.
(författare)
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Long-term effects of no-take zones in Swedish waters
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Marine protected areas (MPAs) are increasingly established worldwide to protect and restore degraded ecosystems. However, the level of protection varies among MPAs and has been found to affect the outcome of the closure. In no-take zones (NTZs), no fishing or extraction of marine organisms is allowed. The EU Commission recently committed to protect 30% of European waters by 2030 through the updated Biodiversity Strategy. Importantly, one third of these 30% should be of strict protection. Exactly what is meant by strict protection is not entirely clear, but fishing would likely have to be fully or largely prohibited in these areas. This new target for strictly protected areas highlights the need to evaluate the ecological effects of NTZs, particularly in regions like northern Europe where such evaluations are scarce. The Swedish NTZs made up approximately two thirds of the total areal extent of NTZs in Europe a decade ago. Given that these areas have been closed for at least 10 years and can provide insights into long-term effects of NTZs on fish and ecosystems, they are of broad interest in light of the new 10% strict protection by 2030 commitment by EU member states.In total, eight NTZs in Swedish coastal and offshore waters were evaluated in the current report, with respect to primarily the responses of focal species for the conservation measure, but in some of the areas also ecosystem responses. Five of the NTZs were established in 2009-2011, as part of a government commission, while the other three had been established earlier. The results of the evaluations are presented in a synthesis and also in separate, more detailed chapters for each of the eight NTZs. Overall, the results suggest that NTZs can increase abundances and biomasses of fish and decapod crustaceans, given that the closed areas are strategically placed and of an appropriate size in relation to the life cycle of the focal species. A meta-regression of the effects on focal species of the NTZs showed that CPUE was on average 2.6 times higher after three years of protection, and 3.8 times higher than in the fished reference areas after six years of protection. The proportion of old and large individuals increased in most NTZs, and thereby also the reproductive potential of populations. The increase in abundance of large predatory fish also likely contributed to restoring ecosystem functions, such as top-down control. These effects appeared after a 5-year period and in many cases remained and continued to increase in the longer term (>10 years). In the two areas where cod was the focal species of the NTZs, positive responses were weak, likely as an effect of long-term past, and in the Kattegat still present, recruitment overfishing. In the Baltic Sea, predation by grey seal and cormorant was in some cases so high that it likely counteracted the positive effects of removing fisheries and led to stock declines in the NTZs. In most cases, the introduction of the NTZs has likely decreased the total fishing effort rather than displacing it to adjacent areas. In the Kattegat NTZ, however, the purpose was explicitly to displace an unselective coastal mixed bottom-trawl fishery targeting Norway lobster and flatfish to areas where the bycatches of mature cod were smaller. In two areas that were reopened to fishing after 5 years, the positive effects of the NTZs on fish stocks eroded quickly to pre-closure levels despite that the areas remained closed during the spawning period, highlighting that permanent closures may be necessary to maintain positive effects.We conclude from the Swedish case studies that NTZs may well function as a complement to other fisheries management measures, such as catch, effort and gear regulations. The experiences from the current evaluation show that NTZs can be an important tool for fisheries management especially for local coastal fish populations and areas with mixed fisheries, as well as in cases where there is a need to counteract adverse ecosystem effects of fishing. NTZs are also needed as reference for marine environmental management, and for understanding the effects of fishing on fish populations and other ecosystem components in relation to other pressures. MPAs where the protection of both fish and their habitats is combined may be an important instrument for ecosystembased management, where the recovery of large predatory fish may lead to a restoration of important ecosystem functions and contribute to improving decayed habitats.With the new Biodiversity Strategy, EUs level of ambition for marine conservation increases significantly, with the goal of 30% of coastal and marine waters protected by 2030, and, importantly, one third of these areas being strictly protected. From a conservation perspective, rare, sensitive and/or charismatic species or habitats are often in focus when designating MPAs, and displacement of fisheries is then considered an unwanted side effect. However, if the establishment of strictly protected areas also aims to rebuild fish stocks, these MPAs should be placed in heavily fished areas and designed to protect depleted populations by accounting for their home ranges to generate positive outcomes. Thus, extensive displacement of fisheries is required to reach benefits for depleted populations, and need to be accounted for e.g. by specific regulations outside the strictly protected areas. These new extensive EU goals for MPA establishment pose a challenge for management, but at the same time offer an opportunity to bridge the current gap between conservation and fisheries management.
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| 2. |
- Askar, Raad, et al.
(författare)
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Bioavailability of subcutaneous and intramuscular administrated buprenorphine in New Zealand White rabbits
- 2020
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Ingår i: BMC Veterinary Research. - : Springer Science and Business Media LLC. - 1746-6148. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundBuprenorphine is one of the most used analgesics for postoperative pain in rabbits. The recommended dose in rabbits (0.01–0.05 mg/kg) is the same for intravenous (IV), intramuscular (IM), and subcutaneous (SC) administration, despite lack of pharmacokinetic data. Five male and five female New Zealand White rabbits (mean ± SD body weight 3.1 ± 0.3 kg) were administered 0.05 mg/kg buprenorphine by the IV, IM and SC routes and 0.1 mg/kg by the SC route, in a cross-over design with two-week wash-out periods between treatments. Blood was collected before, and up to 8 h post buprenorphine injection, for determination of serum levels by UPHLC-MS/MS.ResultsThe area under the time concentration curve (AUC0-t) was lower after SC (398 ± 155 ng/mL/min) than IM (696 ± 168 ng/mL/min, p < 0.001) and IV (789 ± 189 ng/mL/min, p < 0.001) administration. The maximum serum concentration was lower after SC (2.2 ± 1.4 ng/mL) than after IM (11 ± 3.2 ng/mL) administration (p < 0.001). The bioavailability was lower after SC (50 ± 19%) than after IM (95 ± 21%) administration (p = 0.006). The elimination half-life was longer after SC (260 ± 120 min) than after IM (148 ± 26 min, p = 0.002) as well as IV (139 ± 33 min) injection (p < 0.001). An increase in the SC dose from 0.05 to 0.1 mg/kg resulted in an increase in the area under the time concentration curve of 50% in female (p = 0.022) and 165% in male rabbits (p < 0.001). The bioavailability did not change in the females (36 ± 14%, p = 0.6), whereas it increased in the males (71 ± 23%, p = 0.008).ConclusionsThe lower bioavailability of 0.05 mg/kg buprenorphine after SC administration could explain the lack of efficacy seen in clinical pain studies in rabbits, using this route. For immediate pain relief, IV or IM administration is therefore be recommended, whereas SC administration may be useful to sustain analgesic serum levels, once efficient pain relief has been achieved. The current data do not support an increase in dose to compensate for the lower SC bioavailability.
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| 3. |
- Eklöf, Johan S., 1978-, et al.
(författare)
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Effects of seasonal spawning closures on pike (Esox lucius L.) and perch (Perca fluviatilis L.) catches and coastal food webs in the western Baltic Sea
- 2023
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Ingår i: Fisheries Research. - : Elsevier BV. - 0165-7836 .- 1872-6763. ; 263
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Tidskriftsartikel (refereegranskat)abstract
- Marine protected areas have become one of the main tools in the battle to curb marine biodiversity loss and habitat degradation. Yet, implementation of permanent fishery closures has often generated resource user conflicts that ultimately undermine conservation goals. Here we assessed the influence of an alternative and often more accepted measure – seasonal fish spawning closures – on large predatory fish and coastal food webs in the western Baltic Sea (Sweden). In spring 2017, we conducted a multivariable field survey in 11 seasonal closures and 11 paired references areas open to fishing. In each area, pike was sampled through angling, and perch and mesopredators through gillnet surveys. To assess trophic cascades, we measured zooplankton abundance and loss of tethered gammarids from predation. Catches per unit effort of northern pike (Esox lucius) – the main target species in recreational fisheries – were ca. 2.5 times higher per unit effort in closures than reference areas; an effect that may be caused by higher abundance and/or higher catchability of pike in the absence of fishing. Catch and weight per unit effort of the more common predator European perch (Perca fluviatilus), and the mesopredators roach (Rutilus rutilus) and three-spined stickleback (Gasterosteus aculeatus) in survey nets were, however, unaffected by closures. Moreover, a previously hypothesized trophic cascade from perch to zooplankton via three-spined stickleback was supported by the analyses, but appeared independent of closures. Yet, predation risk for tethered gammarid amphipods (a prey of stickleback and an important grazer on macroalgae) was three times higher in fished areas than in closures; a cascading closure effect that may potentially be caused by small predatory fish being less active in protected areas to avoid pike predation. Overall, our results suggest that spawning closures impact pike abundance and/or behavior and could help limit the effects of fishing, but that more research is needed to disentangle i) what mechanism(s) that underlie the protection effect on pike catches, ii) the apparently weaker closure impacts on other fish species, as well as iii) the potential for cascading effects on lower trophic levels. Therefore, new seasonal spawning closures should be implemented in addition to (and not instead of) much-needed permanent closures, which have well-known effects on the wider ecosystem.
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| 4. |
- Berkström, Charlotte, et al.
(författare)
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Rapid effects of a fishing closure on whitefish (Coregonus maraena) in the northern Baltic Sea
- 2021
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Ingår i: Boreal Environment Research. - 1239-6095 .- 1797-2469. ; 26, s. 89-104
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Tidskriftsartikel (refereegranskat)abstract
- Areas closed to fishing year-round (no-take zones, NTZs) or during spawning time (spawning closures) are used as a management tool to increase declining fish populations. We evaluated the effects of a 147 km2 NTZ and a 3980 km2 spawning closure on whitefish populations in the northern Baltic Sea, and also accounted for fish consumption by seals and cormorants. Fish monitoring with multimesh gillnets in 2011–2016 showed a significant increase in catch per unit effort (CPUE) of mature whitefish (> 30 cm) both in the spawning closure and the NTZ compared with the reference area open to fishing. The rate of increase was significantly higher in the NTZ than in the spawning closure. Our results suggest that NTZs may strengthen coastal fish populations in temperate regions and that also seasonal closures under a critical period of the life cycle may benefit the populations.
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| 5. |
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| 6. |
- Bergström, Lena, et al.
(författare)
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Fish community responses to restoration of a eutrophic coastal bay
- 2024
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Ingår i: Ambio. - 0044-7447 .- 1654-7209. ; 53, s. 109-125
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Tidskriftsartikel (refereegranskat)abstract
- Interest in coastal restoration measures is increasing, but information about subsequent ecosystem recovery processes is limited. In Bjornofjarden on the Baltic Sea coast, Stockholm archipelago, a pioneering case study to reduce coastal eutrophication led to improvements and initially halved phosphorus levels. Here, we evaluate the effects of the restoration on the local fish assemblage over one decade after the measures. The study gives a unique possibility to evaluate responses of coastal fish to nutrient variables and abatement in a controlled natural setting. Cyprinid abundance decreased and perch partially increased with decreasing turbidity levels, while mean trophic level increased over time in the restored area. Responses were overall weak, likely attributed to an attenuation of the eutrophication abatement effect over time. The results suggest that nutrient reduction gives slow responses in fish compared to alternative measures such as fishing closures.
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| 7. |
- Bergström, Ulf, et al.
(författare)
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Stickleback increase in the Baltic Sea - A thorny issue for coastal predatory fish
- 2015
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Ingår i: Estuarine, Coastal and Shelf Science. - : Elsevier BV. - 0272-7714 .- 1096-0015. ; 163, s. 134-142
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Tidskriftsartikel (refereegranskat)abstract
- In the Baltic Sea, the mesopredator three-spined stickleback (Gasterosteus aculeatus) spends a large part of its life cycle in the open sea, but reproduces in shallow coastal habitats. In coastal waters, it may occur in high abundances, is a potent predator on eggs and larvae of fish, and has been shown to induce trophic cascades with resulting eutrophication symptoms through regulation of invertebrate grazers. Despite its potential significance for the coastal food web, little is known about its life history and population ecology. This paper provides a description of life history traits, migration patterns and spatiotemporal development of the species in the Baltic Sea during the past decades, and tests the hypothesis that stickleback may have a negative impact on populations of coastal predatory fish. Offshore and coastal data during the last 30 years show that stickleback has increased fourfold in the Bothnian Sea, 45-fold in the Central Baltic Sea and sevenfold in the Southern Baltic Sea. The abundances are similar in the two northern basins, and two orders of magnitude lower in the Southern Baltic Sea. The coastward spawning migration of sticklebacks from offshore areas peaks in early May, with most spawners being two years of age at a mean length of 65 mm. The early juvenile stage is spent at the coast, whereafter sticklebacks perform a seaward feeding migration in early autumn at a size of around 35 mm. A negative spatial relation between the abundance of stickleback and early life stages of perch and pike at coastal spawning areas was observed in spatial survey data, indicating strong interactions between the species. A negative temporal relationship was observed also between adult perch and stickleback in coastal fish monitoring programmes supporting the hypothesis that stickleback may have negative population level effects on coastal fish predators. The recent increase in stickleback populations in different basins of the Baltic Sea in combination with negative spatiotemporal patterns and previously observed interactions between stickleback and coastal predatory fish suggests that this species may have gained a key role in the coastal food webs of the Baltic Sea. Through its migrations, stickleback may also constitute an important vector linking coastal and open sea ecosystem dynamics. (c) 2015 Elsevier Ltd. All rights reserved.
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| 8. |
- Erlandsson, Mårten, et al.
(författare)
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Kartering av uppväxtområden för fisk i grunda områden i Östersjön
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I kust- och havsförvaltningen är behovet av heltäckande utbredningskartor över viktiga fiskhabitat stort både på regional och på nationell nivå. Kartorna efterfrågas för både fiskförvaltning, områdesskydd och havsplanering, liksom för hanteringen av tillstånds- och dispensärenden. Habitatmodellering där man kopplar förekomst av arter i provfisken till olika miljövariabler och på så sätt predikterar lämpliga habitat är en metod som gör det möjligt att ta fram heltäckande utbredningskartor utifrån provfiskedata. Hos många fiskarter är speciellt de yngre livsstadierna starkast knutna till specifika miljöer, vilket dels gör dem extra känsliga för påverkan i dessa områden. Samtidigt gör detta dem lämpliga att kartlägga med hjälp av modellering. I denna studie har vi tagit fram heltäckande, högupplösta kartor över uppväxtområden för ett tjugotal av de viktigaste fiskarterna i grunda områden längs svenska kusten i Östersjön. Vi har använt så kallad ensemblemodellering, där ett flertal statistiska metoder kombineras, för att predicera så säkra utbredningskartor som möjligt. Modellerna bygger på data på yngelförekomst under sensommaren, baserat på provfisken utförda med små undervattensdetonationer under sensommaren, i kombination med data på sex miljövariabler (djup, vågexponering, siktdjup, temperatur, salinitet och avstånd till utsjön). Totalt har 5 867 prover från åren 2005– 2018 ingått i modelleringen. Kartorna täcker in kuststräckan från norra Bottenviken till norra delen av skånska kusten, och 0–6 m djup, som utgör huvudsakligt utbredningsområde för merparten av de modellerade arterna. De predicerade utbredningskartorna är användbara till exempel inom fiskförvaltning, havsplanering, arbete med grön infrastruktur och områdesskydd på både nationell och regional nivå.
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| 9. |
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| 10. |
- Fredriksson, Ronny, et al.
(författare)
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Kartering av uppväxtområden för fisk och större kräftdjur i grunda områden i Västerhavet
- 2021
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Ingår i: Aqua reports.
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- I kust- och havsförvaltningen är behovet av heltäckande utbredningskartor över viktiga fiskhabitat stort både på regional och nationell nivå. Kartorna efterfrågas för både fiskförvaltning, områdesskydd och havsplanering, liksom för hanteringen av tillstånds- och dispensärenden. Habitatmodellering där man kopplar förekomst av arter i provfisken till olika miljövariabler och på så sätt predikterar lämpliga habitat är en metod som gör det möjligt att ta fram heltäckande utbredningskartor utifrån provfiskedata. Hos många fiskarter är speciellt de yngre livsstadierna starkast knutna till specifika miljöer, vilket dels gör dem extra känsliga för påverkan i dessa områden. Samtidigt gör detta dem lämpliga att kartlägga med hjälp av modellering. I denna studie har vi tagit fram heltäckande, högupplösta kartor över uppväxtområden för ett tjugotal av de viktigaste fiskarterna i grunda områden längs svenska västkusten. Vi har använt så kallad ensemblemodellering, där ett flertal statistiska metoder kombineras, för att predicera så säkra utbredningskartor som möjligt. Modellerna bygger på förekomstdata från provfisken utförda med ryssjor under maj till september, i kombination med data på fem miljövariabler (djup, rugositet, vågexponering, temperatur och salinitet). Totalt har 5 146 prover från åren 2002-2017 ingått i modelleringen. Kartorna täcker kustområden ner till 30 meter djup i Skagerrak, Kattegatt och Öresund, vilket utgör huvudsakligt utbredningsområde i svenskt vatten för merparten av de modellerade arterna. De predicerade utbredningskartorna är användbara till exempel inom fiskförvaltning, havsplanering, arbete med grön infrastruktur och områdesskydd på både nationell och regional nivå.
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