JavaScript is disabled in your browser - some features of this site will not work without it [more]

Marine Productivity (MarProd)

UK GLOBEC Meeting - 26 February 2004

Poster presentations

Ecosystems dynamics in UK shelf seas and northern North Atlantic: an overview of the UK GLOBEC programme
P Williamson and M R Heath on behalf of the NERC Marine Productivity programme
ICES/GLOBEC Cod and Climate Change programme (714 KB)
K Brander
Regional environmental change drives long-term community changes in British marine fish
M J Genner, D W Sims, A J Southward & S J Hawkins
Modelling Atlantic salmon growth and survival (212 KB)
D J Booker, P E Ward, N C Wells and I P Smith
The effect of interannual water masses change on fish larvae community in summer: NW Alboran Sea (Western Mediterranean) (588 KB)
P Mafalda Jr, J P Rubin and C Sampaio de Souza
Vertical distribution of Temora stylifera and T. longicornis (SW Bay of Biscay)
N Rodríguez and F Álvarez-Marqués
A molecular method of discriminating species from the small size fraction of mesozooplankton (360 KB)
L Blanco-Bercial and F Álvarez-Marqués
Fluctuating North Sea jellyfish abundance and climate: links to the NAO (217 KB)
C P Lynam, S J Hay and A S Brierley
Interannual variability in the Irminger Basin spring bloom (1179 KB)
S Henson, J T Allen and I Robinson
A large diatom standing stock maintained in a silicon depleted unstable frontal jet
J T Allen, L Brown and M I Lucas
Phytoplankton productivity and nutrient biogeochemical cycling during the Marine Productivity programme, 2002
L Brown, R Sanders, M Lucas, S Henson, P Holliday and J Waniek
Microzooplankton matter: spring ciliate abundance, biomass and production in the Irminger Basin, North Atlantic.
D Wilson
Standardising parameters for marine productivity: a UK and international approach
D Montagnes, D Wilson and G Moncoiffé
Phylogeography of the copepod Calanus finmarchicus in the North Atlantic
J Provan, N McAreavy, G Savidge and C Maggs
Feeding and egg production of Oithona similis in the North Atlantic (248 KB)
C Castellani, X Irigoien, R P Harris and R S Lampitt
Zooplankton production in the Irminger Sea: an enzymatic approach
L Yebra and R P Harris
Calanus the cannibal
D Bonnet, J Titelman, R P Harris and T Smith

Abstracts

Ecosystems dynamics in UK shelf seas and northern North Atlantic: an overview of the UK GLOBEC programme
Phil Williamson¹ and Michael R Heath² on behalf of the NERC Marine Productivity programme

¹ School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ
² FRS Marine Laboratory, PO Box 101, Victoria Road, Aberdeen AB11 9BD

The main UK science contribution to GLOBEC is the Marine Productivity directed programme (£6m; 2000-2005), with lead support by the Natural Environment Research Council. Overall objectives are to develop coupled modelling and observation systems for the pelagic ecosystem, with emphasis on physical factors affecting zooplankton population dynamics. Over 16 research groups are involved, at universities, NERC Centres, fishery laboratories and other research institutions. Highlights of initial shelf sea studies included high resolution 3D modelling of the Irish Sea, taking account of biological processes and allowing for zooplankton-specific applications; eg the effects of daily vertical migration on particle trajectories. Later work in the northern North Atlantic (Irminger Basin and Iceland Basin), included four multidisciplinary research cruises, two in early winter, to determine the seasonal changes in 3D abundances of Calanus finmarchicus and other key zooplankton species. The distributional information is complemented by biochemical, taxonomic, genetic and historical analyses, on-board experimental studies, remote sensing data and novel modelling approaches.

ICES/GLOBEC Cod and Climate Change Programme
Keith Brander

ICES/GLOBEC Coordinator, International Council for the Exploration of the Sea, Palægade 2-4, 1261 Copenhagen K, Denmark

Cod and Climate Change is a regional component of the international GLOBEC programme. A working group of ICES has been running the programme for ten years, with cooperative workshops, theme sessions and comparative studies. Cod (Gadus morhua) is a major component of most North Atlantic ecosystems. Its biology is well known and its abundance and distribution are sensitive to environmental variability. A range of scientific disciplines and scales of investigation has been applied, from the effects of small-scale turbulence on encounter between fish larvae and their prey, to large-scale effects of interdecadal changes in wind fields on circulation and transport of heat, plankton and young fish. Some of these results will be presented, together with references and links to a large body of further material.

Regional environmental change drives long-term community changes in
British marine fish
Martin J. Genner, David W. Sims, Alan J. Southward and Stephen Hawkins

Marine Biological Association, The Laboratory, Citadel Hill, Plymouth, PLl 2PB

Climate change and fishing exploitation have been implicated as the cause of abundance fluctuations in marine fish populations worldwide but the effects on whole communities are poorly understood. Long-term data on the abundance of larval fish in the plankton, immature fish in nursery areas and adult fish on demersal trawling grounds have been collected off south-west Britain between 1913 and 2003. Here we show that climate change has had dramatic effects on population abundance of early life-history stages in the plankton and community composition of later stages. In estuarine (nursery) and offshore areas the prominent patterns of community-level change in assemblages were related to temperature. Each assemblage contained a subset of dominant species whose abundance was strongly linked to annual mean sea-surface temperature. Similar temperature-dependent changes in crustacean prey assemblages are also present suggesting trophic interactions may also have contributed to the observed changes in dominant fish species. Given the documented effects of fishing, this additional evidence suggests that models incorporating both fisheries and climate-mediated environmental parameters are required for better management of fish populations.

Modelling Atlantic salmon growth and survival
D.J. Booker ¹, P.E. Ward², N.C. Wells² and I.P. Smith³

¹Centre of Ecology and Hydrology, Wallingford, Oxon, OX10 8BB.
²Southampton Oceanography Centre, European Way, Southampton, SO14 3ZH.
³University Marine Biological Station, Millport, Isle of Cumbrae, KA28 0EG.

Atlantic salmon (Salmo salar) populations have declined greatly over the past 10-20 years. While in some populations, there may be causal factors during the freshwater phase of the life cycle, there are indications of a widespread increase in mortality during the marine phase. Little is known about the effects of marine conditions on salmon populations, but there is mounting evidence that factors associated with sea surface temperature strongly influence growth and survival. This poster describes the early development of a bioenergetic model to predict energy balance, growth and survival of individual salmon during their marine phase. The boundary conditions for the model are near-surface ocean currents, SST and salmon prey availability. Near-surface ocean currents have been extracted from a high resolution ocean circulation model (OCCAM). SST is gained from the HadlSST 1-degree sea surface temperature climatology (Met Office). Prey availability is derived from a coupled physical-biogeochemical model of the ocean carbon cycle (HadOCC). This individual-based modelling approach will help in assessing past and future changes in the abundance and distribution of salmon returning to the UK, including those caused by climate change. Similar models could also be applied to other fish species.

The effect of interannual changes in water masses on fish larvae community in summer: NW Alboran Sea (Western Mediterranean)
Paulo Mafalda Jr.¹, Juan P. Rubin and Christiane Sampaio de Souza²

¹Instituto Español de Oceanografia - Centro Oceanográfico de Málaga (IEO) SPAIN.
²Universidade Federal da Bahia, Brazil

The ‘Ictio.Alboran-0793’ and ‘Ictio.Alboran-0794’ multidisciplinary oceanographic surveys carried out on the RV Francisco de Paula Navarro, in July 1993 and 1994, by the Instituto Español de Oceanografía (IEO). In this paper we discuss the observed interannual changes in the water masses versus fish larvae (neritic and oceanic species) composition and spatial distribution, in the 19 selected stations at the NW Alboran Sea (Western Mediterranean). Oceanic fish larvae are dominant in both surveys: 62,3 % of the total caught (July 1993) and 63,5 % (July 1994), with major differences between stations. Between the dominant taxa only two neritic taxa (Sparidae and Cepola rubescens) and five oceanic taxa (Ceratoscopleus maderensis, Mauroliccus muelleri, Benthosema glaciale, Hygophum benoiti and Capros aper) are present in both surveys. The stations and taxons dendrogram are divided the study area in to two large sectors, but in different spatial locations: Littoral sector (neritic taxa) / Oceanic sector (oceanic taxa), in 1993; and Western sector (oceanic taxa) / Eastern sector (neritic taxa), in 1994. Temperature is more important factor than salinity in the linkage between waters masses and fish larvae distribution.

Vertical distribution of Temora stylifera and T. longicornis (SW Bay of Biscay)
Nieves Rodríguez and Florentina Álvarez-Marqués

Dpto. Biología de Organismos y Sistemas – Zoología, Universidad de Oviedo, 33207Oviedo, Spain

Since the nineties, the abundance of Temora stylifera in the Cantabrian Sea has built up, in line with the increase in water temperature, whereas T. longicornis has slightly decreased. To improve the knowledge of its population dynamics a study about its vertical distribution was initiated in August 2003. Here we present initial results. On August under highly stratified conditions Temora spp. showed a bimodal distribution, Temora stylifera was restricted to the euphotic layer, and are found mainly in the upper 30 m of the water column, while T. longicornis was found abundantly below the thermocline. This distribution, around the thermocline, coincides with the results obtained in 1989 in this same area.

A molecular method of discriminating species from the small size
fraction of mesozooplankton
Leocadio Blanco-Bercial and Florentina Álvarez-Marqués

Dpto. Biología de Organismos y Sistemas-Zoología, Universidad de Oviedo
C/Catedrático Rodrigo Uría, s/n, 33071 Oviedo, Asturias, Spain

Traditionally, zooplankton studies have been carried out on the larger species and the later developmental stages, at least in the case of copepods. This fact has been due to the difficulty of distinguishing between all the (morphologically) very similar species and genus, especially at immature stages. But nowadays, the molecular techniques allow us to discriminate these species easily. Then, we have developed a RFLP technique to distinguish between some species of the genus Clausocalanus which are present at our study zone. This genus belongs to the “small” fraction of mesozooplankton (500-200mm), and it has been scarcely studied even though it is an important component of the mesozooplankton. We present the results of the procedure, resulting from the digestion with the restriction enzyme Mbo I of the amplified region of the COI gene, carried out on four species in practice (and on seven species theoretically). Nowadays, we are using this tool on the research on the biology, vertical distribution and ecological features of these species, including the copepodites from the different species.

Fluctuating North Sea jellyfish abundance and climate: links to the NAO
Christopher P. Lynam¹, Steve J. Hay² and Andrew S. Brierley¹

¹Pelagic Ecology Research Group, Gatty Marine Laboratory, University of St Andrews, KY16 8LB
² Fisheries Research Services Aberdeen, Victoria Road, Torry, Aberdeen, AB11 8DB

The abundance of jellyfish (Phylum Cnidaria, Class Scyphozoa) is increasing in numerous marine ecosystems worldwide, perhaps as a consequence of 'regime shifts' associated with climatic change and/or increasing fishing pressure. Jellyfish have the potential to interact with fisheries in both 'top down' and 'bottom up' competitive processes: jellyfish medusae may consume large numbers of zooplankton (including copepods) that could otherwise be food for fish, and may also consume fish eggs and larvae. We have shown (Lynam et al. 2004. Interannual variability in abundance of North Sea jellyfish and links to the North Atlantic Oscillation. Limnology and Oceanography, in press) that the abundance of two species of jellyfish (Aurelia aurita and Cyanea lamarckii) in the North Sea is significantly correlated with the winter index of the North Atlantic Oscillation (NAO).

The NAO has been identified as a possible contributory factor influencing the abundance of numerous North Sea fish species. We suggest that jellyfish may be an as-yet-overlooked intermediary linking fisheries to climate. The NAO index is presently in a high phase, thus the resulting hydroclimatic conditions in the North Sea may be depressing jellyfish abundance. If the NAO index reverses, environmental controls on jellyfish may be relaxed allowing these gelatinous zooplankters to proliferate, which in turn may hinder the recovery of fish stocks even in the absence of fishing.

Interannual variability in the Irminger Basin spring bloom
Stephanie Henson, John Allen, Richard Sanders, Louise Brown and Ian Robinson

Southampton Oceanography Centre, European Way, Southampton, SO14 3ZH

The magnitude of the spring bloom in high latitudes is thought to be controlled by factors such as wind speed and pre-bloom nutrient concentrations. Understanding the variability in the bloom is crucial for quantifying export production and energy transfer to higher trophic levels. Six years (1998-2003) of satellite ocean colour derived chlorophyll concentration for the Irminger Basin shows significant interannual variability in the magnitude of the spring bloom. The bloom of 2002 is considerably reduced in comparison to other years. Pre-bloom nitrate concentrations are estimated from satellite sea surface temperature and chlorophyll concentration. Although similar nitrate concentrations as for other years are available for 2002, chlorophyll concentrations remain low throughout the year. We suggest that meteorological factors, such as wind speed and heat flux were limiting the 2002 bloom.

A large diatom standing stock maintained in a silicon-depleted
unstable frontal jet
John T. Allen, Louise Brown and Mike I. Lucas

Southampton Oceanography Centre, European Way, Southampton, SO14 3ZH

During the FISHES research cruise (2001), 15N and 32Si uptake incubation experiments were carried out in the Iceland Basin. 32Si incubation experiments were novel in this part of the North Atlantic and indicated that uptake rates were reduced at concentrations less than 2 µM. Over the entire basin dissolved silica concentrations were low, and potentially limiting for optimum uptake rates apart from just south of the Iceland Faeroes Front (IFF). However, a silica uptake station in the frontal jet showed a high diatom standing stock and non-zero silica uptake. Subsequent high resolution surveys of the frontal zone supported the view that this incubation did not just observe a rapidly transient end of bloom state. Satellite ocean colour also confirmed that high chlorophyll concentration was maintained both spatially and temporally over the convoluted frontal jet. Upwelling of water associated with mesoscale instability of the IFF has been diagnosed and is presented as the mechanism behind the biological observations. Furthermore, we use a scaling analysis of the vertical exchange of water, effected by baroclinic instability, to infer a magnitude for biogenic silica export.

Phytoplankton productivity and nutrient biogeochemical cycling during the Marine Productivity programme, 2002
Louise Brown, Richard Sanders, Mike Lucas, Stephanie Henson, Pennie Holliday and Joanna Waniek

Southampton Oceanography Centre, European Way, Southampton, SO14 3ZH

Phytoplankton productivity and distribution in the western North Atlantic over a seasonal cycle were examined during the Marine Productivity programme to assess the potential influence of bottom-up control on zooplankton distribution, using inorganic and total nutrient data, phytoplankton taxonomy, phytoplankton carbon uptake, and satellite imagery. Spring bloom production, dominated by the prymnesiophyte Phaeocystis occurred earliest along the northwestern Greenland margin, initiated by meltwater-induced stratification prior to the spring cruise. Satellite imagery indicated the bloom in the central basin peaked during June and July, reducing surface silicate and nitrate concentrations to an average of 2 and 6 µmol L-1 respectively. Estimates of annual new production give values of 33-80 gC m-2 y-1 across the central basin. With the exception of the coastal stations, no geographical variation in the timing or extent of the bloom was clear from the cruise nutrient data alone, although fluorescence and satellite chlorophyll data may indicate early bloom initiation along the Reykjanes ridge and the north of the basin. Using data from the central (DD) transect, it appeared approximately 50 % of nitrate utilised between spring and summer was stored as DON in the surface 300 m, substantially reducing the new production available for export to higher trophic levels.

Microzooplankton matter: spring ciliate abundance, biomass and production in the Irminger Basin, North Atlantic
Dave Wilson

University of Liverpool, School of Biological Sciences, Bioscience Building, Crown Street, Liverpool, L69 7ZB

Ciliates are often the dominant marine planktonic heterotrophs. They feed on particles too small for copepods to capture but in turn are eaten by copepods, providing a link in the transfer of primary production to higher trophic levels. Understanding ciliate distribution, both in terms of numbers and production is therefore important when investigating carbon flux in oceanic food webs. This poster examines ciliate distribution during the spring in the Irminger Basin, the focus region in the interdisciplinary NERC Marine Productivity programme.

Surface and mid-water samples, fixed in 10% Lugol’s, assessed the upper mixed layer at ~30 sites between 18 April – 27 May 2002. Ciliate biodiversity and abundance were determined using light microscopy. Ciliate biovolume was determined using image analysis and converted to biomass assuming 190 fg C µm-3. Ciliate production was calculated as the product of species biomass and species growth rate, the latter estimated from a predictive relationship that relies on ambient temperature and cell volume. Over 50 species occurred, with dominants being the autotrophic ciliate Myrionecta rubra and a small strombidiid; distinct species-distributions existed, potentially associated with water masses. The impact of biomass and production estimates will be discussed in the larger food web context.

Standardising parameters for marine productivity: a UK and international approach
David Montagnes¹, David Wilson¹ and Gwen Moncoiffé²

¹School of Biological Sciences, University of Liverpool, Liverpool, L69 7ZB
²British Oceanographic Data Centre, Bidston Observatory, Bidston Hill, Prenton, Merseyside, CH43 7RA

The UK Marine Productivity programme (MarProd), a GLOBEC affiliate, is examining zooplankton production in poorly characterised north-western Atlantic waters. There have been four interdisciplinary cruises, which measured biotic and abiotic factors affecting zooplankton. Sample analysis is now reaching completion for most research groups, and data are being compiled for both individual studies and collaborative, interdisciplinary studies, at a variety of levels. However, the MarProd community recognises the lack of consistency between groups in their application of conversion factors and model-parameters; e.g. it is recognised that Lugol’s iodine, the recommended fixative for phyto- and microzooplankton, shrinks cells. Conversion factors from cell volume to biomass thus depend on knowing the magnitude of this shrinkage, but we lack a consistently used value for this parameter. Similarly, there are a variety of disparate parameters applied to zooplankton biomass and production estimates. Parameters associated with a single estimate (e.g. cell shrinkage) may differ by only 10%, but integrative studies will compound these, and multiplicative biases may lead to erroneous order-of-magnitude differences between studies. This poster describes how MarProd is solving this dilemma by producing standard “fact sheets” that will assemble and disseminate standard values. Information for these can be obtained from the BODC MarProd web site or from David Montagnes.

Phylogeography of the copepod Calanus finmarchicus in the North Atlantic
Jim Provan¹, Nicola McAreavy¹, Graham Savidge² and Christine Maggs¹

¹Queen’s University of Belfast, School of Biology and Biochemistry, Medical Biology Centre, 97 Lisburn Road, Belfast, BT9 7BL

²Queen’s University of Belfast, Marine Laboratory, Portaferry, Co Down, BT 22 1PF

The cool water marine copepod Calanus finmarchicus is the dominant contributor, in terms of biomass, to the mesozooplankton in the northern North Atlantic and also in the adjacent Norwegian Sea. These areas are highly dynamic, exhibiting strong advective drift in certain sectors, particularly associated with the North Atlantic Current (NAC) and its extension into the Norwegian Sea. In addition a number of gyres are clearly defined within the surface layers of the area. We have used molecular approaches to determine whether population substructuring occurs in C. finmarchicus and if so, whether such substructuring is determined by current systems. Analysis of the pseudogene copy of the mitochondrial coxI gene suggests that there is little genetic structure and implies a rapid and recent radiation of the species, probably through the Pleistocene glaciation. High-resolution microsatellite markers currently under development in our laboratory will be employed to further investigate these results.

Feeding and egg production of Oithona similis in the North Atlantic
Claudia Castellani ^1,4 Xabier Irigoien² Roger Harris³ and Richard Lampitt¹

¹Southampton Oceanography Centre, European Way, Southampton, SO14 3ZH
² AZTI, Herrera Kaia Portualdea, 20110 Pasaia, Spain
³Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH
⁴Present address: Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH

Although cyclopoids of the genus Oithona are considered the most abundant copepods in the marine environment there is still very little information about what sustains their population and almost constant reproduction rate throughout the year. Feeding and egg production rate (EPR) of Oithona similis were measured at coastal and oceanic stations during three cruises in the North Atlantic between April and November 2002. O. similis ingested ciliates preferentially to other components of the microplankton which only become important when the concentration of the former decreased to very low concentrations. EPR did not show significant seasonal differences, 2.13 ± 0.67 eggs fem-1 d-1 in spring, 1.61 ± 0.32 eggs fem-1 d-1 in summer and 1.60 ± 0.15 eggs fem-1 d-1 in winter. The ingestion rates measured at many oceanic stations and in winter were often too low to sustain EPR. Egg production efficiency >100 % indicated that sustained EPR might have relied, particularly in winter, on alternative food sources such as a more carnivorous diet and/or on the faecal pellets of euphausids.

Zooplankton production in the Irminger Sea: an enzymatic approach
Lidia Yebra and Roger Harris

Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH

Spatial distribution of zooplankton biomass and structural growth were studied during the summer of 2002 in the Irminger Sea, with special emphasis on the calanoid copepod Calanus finmarchicus. A new enzymatic approach, the aminoacyl-tRNA synthetases activity (AARS, Yebra and Hernández-León, 2004, J. Plankton Res. 26(3)) was used as index of population growth. Mesozooplankton biomass distribution varied according to hydrography and chlorophyll concentration changes. The front located in the Irminger basin enhanced growth rates of C. finmarchicus and zooplankton in the 200-450µm range size, while the 63-200µm fraction showed higher AARS values in the Greenland shelf.

Calanus the cannibal
Delphine Bonnet¹, Josefin Titelman ^1,2, Roger P. Harris¹ and T. Smith¹

¹Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH
²University of Bergen, Department of Fisheries and Marine Biology, PO Box 7800-N 5020 Bergen, Norway.

Recent modelling efforts have suggested that cannibalism on eggs and young nauplii are an important factor controlling the population dynamics of Calanus. We measured cannibalistic feeding rates on eggs and nauplii of Calanus helgolandicus in the laboratory. Clearance rates were highly variable on nauplii (0-31 mL ind-1 d-1), while generally high on eggs (320 mL ind-1 d-1). Female starvation did not affect ingestion of eggs. We discuss our results in light of published model predictions, cannibalistic feeding rates of other copepods and field distributions of Calanus developmental stages.

Related Marine Productivity pages at BODC

Oral Presentations at UK GLOBEC meeting 2004		BODC processing
Contents		Cruise programme
Project overview		Data inventories
BODC's role		Data delivery
Data policy		Project Specific
Data submission		Other links

Related external pages

Official MarProd web site

Global Ocean Ecosystem Dynamics (GLOBEC)