Long-term trends in ten non-target North Sea fish species

The distribution, abundance and seasonal occurrence of larvae of mackerel (Scomber scombrus L.) are described from routine Continuous Plankton Recorder (CPR) sampling around the British Isles over the period 1948–78, and from more intensive CPR sampling in the Celtic Sea in 1977. There were two main areas of larval concentration: in the North Sea and over and adjacent to the Celtic Plateau; subsidiary aggregations were observed to the northwest of Ireland and to the west of Norway. There were some similarities between the distribution of larvae around the British Isles and that of adult Calanus spp. In the North Sea there was a southerly shift of larval distribution over the period 1948–77; over a similar period the abundance of larvae increased to reach high numbers by the late 1950s and subsequently declined after the mid-6os. To the south-west of the British Isles numbers of larvae showed a long-term decline. The long-term trends of distribution and abundance are discussed in relation to concurrent biological and environmental change. The clearest relationship was found between the numbers of mackerel larvae in the North Sea and sea-surface temperature in the North Atlantic, which suggests a common causative agent for both sets of observations; also, there was a weak relationship with both spawning stock biomass and sea-surface temperature at the spawning areas. In the North Sea the seasonal occurrence of larvae was from May to August, the majority being taken in June and July; over the period 1948–77 the seasonal time of occurrence of highest numbers of larvae has remained relatively constant. In the Celtic Sea the seasonal occurrence of larvae was spread over a longer period, from March to August, with relatively high numbers from March to June; over the period 1950–78 the time of occurrence has been variable, possibly with a tendency towards later timing in more recent years.

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Entering uncharted waters: Long-term dynamics of two data limited fish species, turbot and brill, in the North Sea

Journal of Sea Research ◽

10.1016/j.seares.2013.07.005 ◽

2013 ◽

Vol 84 ◽

pp. 87-95 ◽

Cited By ~ 8

Author(s):

Tina K. Kerby ◽

William W.L. Cheung ◽

Cock van Oosterhout ◽

Georg H. Engelhard

Keyword(s):

North Sea ◽

Fish Species ◽

The North ◽

The North Sea

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Long Term Trends in the Occurrence of Phaeocystis Sp. in the North-East Atlantic

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400032185 ◽

1989 ◽

Vol 69 (4) ◽

pp. 813-821 ◽

Cited By ~ 35

Author(s):

N.J.P. Owens ◽

D. Cook ◽

M. Colebrook ◽

H. Hunt ◽

P.C. Reid

Keyword(s):

North Sea ◽

Plant Biomass ◽

Nitrogen And Phosphorus ◽

Sulphur Compounds ◽

North East ◽

The North ◽

The North Sea ◽

Long Term Trends ◽

Flagellate Algae

The effects of nutrient enrichment of natural water bodies range from small increases in plant biomass and production, to gross deterioration of water quality. The input of nutrients (e.g. nitrogen and phosphorus) to the sea off NW Europe (especially the North Sea) has increased dramatically over the last three or four decades (Folkard & Jones, 1974; Bennekom et al., 1975; Postma, 1978; Cadee, 1986a) but there is uncertainty about the effects on the ecosystem. One possible effect might be to induce changes in the phytoplankton community. Such an effect has been reported for the North Sea, where increases in flagellate algae have been observed (Gieskes & Kraay, 1977; Postma, 1985; Cadee, 1986b; Batje & Michaelis, 1986). Phaeocystis is one such alga, and its purported involvement in the formation of large quantities of foam, observed on European beaches (Batje & Michaelis, 1986; Weisse et al, 1986), together with evidence that the alga is a source of atmospheric sulphur compounds (Barnard et al, 1984) (with implications for atmospheric acidity), has attracted particular attention and concern

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Long-term trends in the central-west North Sea

Senckenbergiana maritima ◽

10.1007/bf03043022 ◽

2001 ◽

Vol 31 (2) ◽

pp. 117-124 ◽

Cited By ~ 3

Author(s):

Robin A. Clark ◽

Chris L. J. Frid

Keyword(s):

North Sea ◽

Long Term Trends

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Modelling the direct impact of bottom trawling on the North Sea fish community to derive estimates of fishing mortality for non-target fish species

ICES Journal of Marine Science ◽

10.1093/icesjms/fsp162 ◽

2009 ◽

Vol 66 (9) ◽

pp. 1985-1998 ◽

Cited By ~ 32

Author(s):

G. J. Piet ◽

R. van Hal ◽

S. P. R. Greenstreet

Keyword(s):

North Sea ◽

Fish Species ◽

Fish Community ◽

Direct Impact ◽

Fishing Mortality ◽

Bottom Trawling ◽

The North ◽

Target Fish ◽

The North Sea ◽

Sea Fish

Abstract Piet, G. J., van Hal, R., and Greenstreet, S. P. R. 2009. Modelling the direct impact of bottom trawling on the North Sea fish community to derive estimates of fishing mortality for non-target fish species. – ICES Journal of Marine Science, 66: 1985–1998. This study introduces a spatially explicit model that combines abundance data for all the main fish species in the demersal North Sea fish community with international effort data and estimates of gear-, species-, and size-dependent catch efficiency to determine the mortality of non-target fish species caused by bottom trawl fisheries and its spatial variation. Where necessary information was lacking, assumptions were made, and a sensitivity analysis performed to examine the impact of these issues on model results. Model outcomes were validated using international landings and discard data for five target species: cod, haddock, whiting, sole, and plaice. This showed that depending on its configuration, the model could reproduce recorded landings and discards of these species reasonably well. This suggests that the model could be used to simulate rates of fishing mortality for non-target fish species, for which few data are currently available. Sensitivity analyses revealed that model outcomes were most strongly influenced by the estimates of gear catch efficiency and the extent to which the distributions of fishing effort and each species overlapped. Better data for these processes would enhance the contribution that this type of model could make in supporting an ecosystem approach to fisheries management.

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Long-Term Trends in the Structure and Dynamics of the Fish Communities in Buško Blato Reservoir

Croatian Journal of Fisheries ◽

10.2478/cjf-2020-0007 ◽

2020 ◽

Vol 78 (2) ◽

pp. 69-78

Author(s):

Aldijana Mušović ◽

Rifat Škrijelj ◽

Mahir Gajević ◽

Belma Kalamujić Stroil ◽

Adi Vesnić ◽

...

Keyword(s):

Fish Species ◽

Ecological Factors ◽

Lepomis Gibbosus ◽

Tinca Tinca ◽

Structure And Dynamics ◽

Current State ◽

Long Term Trends ◽

Endemic Fish ◽

First Time

AbstractBuško Blato Reservoir, the third largest hydro accumulation in Europe, is situated in the south-eastern part of the karstic Livanjsko Polje Valley. This aquatic ecosystem is distinguished by a very rich ichthyofauna and the presence of four endemic fish species. Numerous studies focus on ichthyological researches of Buško Blato Reservoir. Its ichthyofauna has been exposed to changes in ecological factors, which in turn reflected on the structure and composition of fish populations. The main objective of this paper was to assess the current state and predict future trends in the ichthyofauna structure and dynamics based on the field data and comprehensive analyses of literature data. The results of the research indicated the presence of 11 fish species from four families, which is the largest number of fish species ever recorded in this ecosystem. Sander lucioperca, Lepomis gibbosus, Pseudorasbora parva and Tinca tinca were recorded for the first time in this ecosystem, while some previously recorded species were not found. The results of the analyses clearly indicate the presence of natural interspecific competition and significant level of threats to the endemic fish species caused by human activities.

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