Ecological Status Report The ecological status of the North Atlantic environment based on observations from the 2009 Continuous Recorder survey

Monitoring the health of the oceans since 1931

Status report summary p.2

Marine climate change impacts p.3

Marine biodiversity and invasive species p.5

Marine ecosystem and environmental health p.7

Ocean acidification p.8

Citation: Edwards, M., Beaugrand, G., Johns, D.G., Licandro, P., McQuatters-Gollop, A. & Wootton, M. 2010. Ecological Status Report: results from the CPR survey 2009. SAHFOS Technical Report, 7: 1-8. Plymouth, U.K. ISSN 1744-0750 STATUS REPORT 2 ocean by carbon sequestration inwhat isknown asthe‘’. Withoutthisprocess concentrations of CO These organisms alsoplay acrucialrole inclimate change through theexport oftheimportant greenhouse gas CO marine mammals)ishighlydependent onvariations intheabundance,timingand compositionoftheplankton. of thesize offish resources and recruitment to individual stocks as well astheabundanceofmarinewildlife seabirds (e.g. and () whichinturnprovide food for many othermarineorganisms. Thecarrying capacity ofmarineecosystems interms At thebaseofmarinefoodweb, thefree floating plant life ofthesea() provide food fortheanimalplankton Plankton asindicators ofthehealthoceans fisheries. biodiversity, pollutionand as climate warming impacts, marine management issues such information for important North Atlantic Oceanandsupplies indicators for thestatus ofthe The following report provides ‘ecological health’ofourseas. essential information onthe environmental change andprovide also highlysensitive indicators of marine foodwebs, plankton are the earth’s climate system andin much higherintheatmosphere andtheclimate oftheworld would bemuchwarmer. Apartfrom playing afundamental role in Status report summary timing ofsomeHarmful Algal Bloomspeciesare related to regional climate warming. number ofmicroplastics collected onCPRsamplesisincreasing andthefrequency ofoccurrence andbloom may alsoexacerbate thesenegative effects inthesevulnerable regions.Ithasalsobeen foundthat the certain coastal areas andthesouthernNorthSeaare notvulnerable to andclimate change the North-East Atlantic asawholeis generally considered to be fairly healthy. This isnot to say, however, that variability asopposedto anthropogenic nutrient inputleadingto input(e.g. eutrophication). Thismeansthat At theregional scale, ithasbeenfound that most phytoplankton trends are related to hydro-climatic Marine ecosystem healthand water quality drawdown. implications for marineecosystem suchassmaller-sized services fish communities and reduced carbon biodiversity isassociated withadecreasing size-structure ofthecommunity. This inturnmay have There isastrong relationship between biodiversity andsize-structure inpelagic communities. Increasing Oceanic plankton biodiversity isincreasing intheNorthAtlantic associated with temperature increases. Marine biodiversity andinvasive species changes are associated withregional climate warming. occurrences ofplankton withothertrophic levels includingfishlarvae. There isahigh confidence that these this change iscurrently considered detrimental because ofthepotential ofmis-timing(mismatch) ofpeak not alltrophic levels are responding to thesameextent; therefore interms ofaproductive environment, warming. For example, somespecieshave moved forward intheirseasonalcycles by 4-5weeks. However, orphenology,Seasonal timing, isoccurringearlierintheNorthSeaand related to regional climate Marine climate change impacts:Changes inseasonalityandphenology warming. by 70%intheNorthSea.There isahighconfidence that thesetrends are related to regional climate impact othertrophic levels includingfishlarvae. For example, animportant zooplankton specieshasdeclined warmer-water speciesare notreplacing thecolder-water speciesinsimilarabundanceswhichmay negatively NAO. Interms ofaproductive environment thischange iscurrently considered detrimental because the Warmer-water speciesare currently increasing intheNorthSeadueto regional climate warming andthe Marine climate change impacts:Northward shifts the future. these vulnerable organisms incase theseorganisms start to show any negative effects due toacidification in andforaminifera. TheCPRsurvey isproviding acritical baselineandiscurrently monitoring Organisms that could beparticularlyvulnerable to acidification are the calcifying organisms suchas ocean acidification; invasive species and marine biodiversity.ocean acidification;invasivespeciesandmarine eutrophication/pollution;Harmful climate changeimpacts;fisheriesandmarinewildlife; Algal Blooms; foroceanicchange: a. Marineplanktonecologicalindicatorsmonitoring Plankton communities as ecological indicators Plankton communitiesasecological in moderntimes. absent fromtheNorthAtlanticforover800,000yearsandcouldbefirstevidenceofatrans-Arcticmigration since thelate1990swhichhasspreadsouthwardsandeastwards.Thediatomspeciesitselfbeen is increasing.TheCPRsurveyhasalreadydocumentedthepresenceofaPacificdiatominLabradorSea From ourknowledgeofcopepods(zooplankton)webelievetheoverallpelagicbiodiversity*NorthSea Biodiversity andinvasivespecies associated withregionalclimatewarming. of planktonwithothertrophiclevels*includingfishlarvae.Thereisahighconfidencethatthesechangesare is currentlyconsidereddetrimentalbecauseofthepotentialmis-timing(mismatch*)peakoccurrences trophic levels*arerespondingtothesameextent;thereforeintermsofaproductiveenvironment,thischange For example,somespecieshavemovedforwardintheirseasonalcyclesby4-5weeks.However,notall Seasonal timing,orphenology*,isoccurringearlierintheNorthSeaandrelatedtoregionalclimatewarming. Changes inseasonality .Thereisahighconfidencethatthesetrendsarerelatedtoregionalclimatewarming. trophic levels*includingfishlarvae.Forexample,animportantzooplanktonspecieshasdeclinedby70%inthe species arenotreplacingthecolder-waterinsimilarabundanceswhichmaynegativelyimpactother In termsofaproductiveenvironmentthischangeiscurrentlyconsidereddetrimentalbecausethewarmer-water Warmer-water speciesarecurrentlyincreasingintheNorthSeaduetoregionalclimatewarmingandNAO. Northward shifts Acidification acidification. to show anynegativeeffectsdueto these vulnerableorganismsincasethefuturestart coccolithophores andforaminifera.TheCPRsurveyisprovingacritic Organisms thatcouldbeparticularlyvulnerabletoacidificationarethe *speciesarerelatedtoregionalclimatewarming. collected onCPRsamplesisincreasingandthefrequencyofoccurrencebloomtimingsomeHarmful these negativeeffectsinvulnerableregions.Ithasalsobeenfoundthatthenumberofmicroplastics* areas andthesouthernNorthSeaarenotvulnerabletoeutrophicationclimatechangemayalsoexacerbate Atlantic asawholeisgenerallyconsideredtobefairlyhealthy.Thisnotsay,however,thatcertaincoastal opposed toanthropogenic*input(e.g.nutrientleadingeutrophication*).ThismeansthattheNorth-East At theregionalscale,ithasbeenfoundthatmostphytoplanktontrendsarerelatedtohydro-climaticvariabilityas Ecosystem healthandwaterquality Sir Alister Hardy Foundation for OceanScience al baselineandiscurrentlymonitoring calcifyingorganismssuchas 2 to thedeep 2 would be STATUS REPORT 3 earlier usually has later in the later is becoming is becoming , a trend that that , a trend °C isotherm and is 2008 was again again 2008 was in the North-East Atlantic Atlantic in the North-East C. finmarchicus C. helgolandicus species. Although copepod and the warm-temperate Calanus and the warm-temperate biomass has declined by 70% since biomass has declined by C; these two species can therefore therefore species can °C; these two C. finmarchicus in Over the last five decades there has been a there decades five the last Over of warm- in the presence increase progressive the more species into water/sub-tropical Atlantic of the North-East areas temperate species. This and a decline of colder-water the over be accelerating seems to trend The mass biogeographical years. five last in sea changes to related are movements interesting A particularly temperature. surface is the decline in years five last the over feature of Iceland to the south-east species subarctic (see the north and west to and their movement left). figure in the trend of the warming indicator A useful is the shift indicator) North Sea (a northward Calanus cold-temperate of the ratio percent finmarchicus helgolandicus do occupy similar they very these species are thermal niches. The thermal boundary distinct copepod distributed the arctic-boreal for Calanus finmarchicus the ~10-11 lies between of major biogeographical indicator a useful Calanus helgolandicus provinces. a northern distributional boundary of 14°C a northern distributional between lying optimum and has a population 10-20 When these in their distributions. overlap for is a tendency there species co-occur two high abundances of dominated by C. helgolandicus by dominated the last over been accelerating has evidently While decade. in the North Sea the overall abundant more Calanus in biomass has reduction the 1960s. This huge other marine for consequences had important in the North Sea including fish larvae. wildlife in the year and C. helgolandicus in the year of thermal niche is clear evidence There year. two species as these between differentiation as successional partitioning in the North well temperatures cooler to related Sea, probably temperatures and warmer earlier in the year in the year. later C. helgolandicus between ratio The percentage and Northward shifts Northward - -

. Cala ) per Subarctic species C. helgolandi ) and a cold-water ) and a cold-water C. finmarchicus ) (0= total (0= total Cold-temperate species Top: Biogeographical changes in changes Biogeographical Top: spanning assemblages plankton Warm-water decades. five (e.g. warm-temperate plankton north moving species) are (e.g. plankton and cold-water moving species) are subarctic out of the North Sea. Based on (2002) 296: 1692-1694 Science Bottom: A simple ratio between a between ratio A simple Bottom: species ( copepod warm-water nus helgolandicus species (Calanus finmarchicus values 1958-2008. Red from month a dominance of the warm- indicate species and blue values water the dominance of the cold-water species. dominance, 1=total cus dominance Marine climate change impacts change climate Marine Temperate species

Sir Alister Hardy Foundation for Ocean Science Foundation Hardy Sir Alister

Warm-temperate species Mean number of species per CPR sample per assemblage Northward shift indicators Northward 1000 km shift northward STATUS REPORT 4 occurred muchearlierthanthelong-term average. seasonal development ofechinodermlarvae has exception of1996(anegative NAO year),the seasonal peak.Since1988inparticular, withthe that there isamajortrend towards anearlier (i.e., thepeakinseasonalappearance). Itisclear larvae from 1958–2008inthecentral NorthSea abundance ‘centre ofgravity ofechinoderm index’ The figure above shows theannualpeakseasonal phenological changes inshelfseaenvironments. larvae asarepresentative indicator of of meroplankton to temperature, we have chosen the sensitivityofphysiological development natural seasonalevents). phenomena(e.g. Dueto Phenology isthestudy ofthetiming recurring Phenology ( ( ( 1958. Basedon 2002 plotted against thetimingoftheirseasonalpeakin for 66plankton taxa over the45-year periodfrom 1958to The change inthetimingofseasonalpeaks (inmonths) Phenological shifts:thechange inthetimingofseasonalpeaks (inmonths) for66plankton taxa over the45-year period c a b ) ) Change in seasonal peak from 1958 to 2002 )

hemispheres. Courtesy ofGoogleEarth. CPR samplesintheNorthernandSouthern Abundance - - - - 2 1 1 0 0 0 1 1 2 1 2 3 4 5 6 ...... 0 0 0 0 0 0 0 5 0 5 0 5 0 5 0 0 0 0 0 0 Month of seasonal peak 0 0 0 0 0 0 0 0 0 0 0 0 0 0 7 8 9 Phenology indicators 1 1 9 1 6 2 0 O M D D C p l i i o t a e 3 1 1 n a h p n 9 9 r o t 1 e o o 8 5 e k 9 2 f 4 r C C 1 8 p m l p t 7

a o - - h l 0 e e o 2 1 a g s n 0days o 0 9 5 r r d n e a a 0 8 l M s o k l 2 0 t t Nature (2004)430:881-884 l i i z a o t 6 1 Y u u o 3 M n o 9 S t e m m e n t 8 o a h p 7 s 0 o r

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C C 1 8 y 3 y 9 l l 1 i i 5 n n 9 4 d 8 d 7 Dinoflagellates 23days A r 0 r o o 5 u t 9 t t h h u M e e 6 1 Y 47days m o c Other meroplankton27days 9 c . e n 8 a n a a 7 t 0

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Late E arly early seasonalappearance ofechinodermlarvae. temperature. Thistrend continued in2008withthe last decade ishighlycorrelated withseasurface appearance ofmeroplanktonic larvae duringthe term mean.Thistrend towards anearlierseasonal occurred upto 4-5weeks earlierthanthelong- For example, inthe1990sseasonalcycle 430:881-884 More information: confidence that thesetrends are related to regional climate warming. of plankton withothertrophic levels includingfish larvae. There isahigh because ofthepotential ofmis-timing(mismatch) ofpeakoccurrences of aproductive environment, thischange is considered detrimental trophic levels are responding to thesameextent, therefore interms moved forward intheirseasonalcycle by 4-5weeks. However, notall is related to regional climate warming. For example, somespecieshave orphenology,Seasonal timing, isoccurringearlierintheNorthSeaand trophic levels includingfishlarvae. species insimilarabundanceswhichhasnegative impactsonother because thewarmer-water speciesare notreplacing thecolder-water terms ofaproductive environment thischange is considered detrimental regional climate warming andtheNorthAtlantic Oscillation (NAO). In Warmer-water speciesare currently increasing intheNorthSeadueto Marine climate change impacts policy makers forSummary Month (phenology index) 8 7 6 5 appearance. seasonal appearance, colder temperatures =late seasonal to presently aJunepeak.Warmer temperatures =earlier in theNorthSeashowing amovement from aJulypeak of echinodermlarvae (anindicator ofplankton phenology) Inter-annual variability inthepeakseasonaldevelopment . . . . 5 5 5 5 5 8 7 6 1 9 5 8 1 9 6 3 1 9 Science (2002)296:1692-1694;Nature(2004) 6 8 1 9 7 3 Sir Alister Hardy Foundation for OceanScience 1 9 7 8 P Y 1 h e 9 e a 8 r n 3 s o 1 l o 9 8 g 8 y 1 9 9 3 1 9 9 8 2 0 0 3 2 0 0 8 STATUS REPORT 5 . . (PNAS (2010) 107: 10120-10124) Long-term latitudinal latitudinal Long-term in carbon changes time residence Long-term latitudinal changes latitudinal Long-term in species diversity parallel decrease in size-structure of pelagic in size-structure decrease parallel have may diversity with increasing organisms services for marine ecosystem implications and communities fish such as smaller-sized (PNAS (2010) 107: drawdown carbon reduced 10120-10124) - - Marine biodiversityMarine species invasive and Oceanic biodiversity and carbon Oceanic biodiversity Mean residence time of Mean residence carbon particulate Total oceanic diversity oceanic Total (Gini diversity) Sir Alister Hardy Foundation for Ocean Science Foundation Hardy Sir Alister Relationships between the spatial distribution and long-term latitudinal changes in the diversity of calanoid diversity in the changes latitudinal and long-term distribution the spatial between Relationships on the performed jackknife by first-order was measured Diversity North Atlantic. in the extratropical residence time diversity and mean of copepod distributions (1960-2007) spatial Left panel: mean Gini coefficient. copepod diversity in changes latitudinal panel: long-term Right particles (in days). 50 m of sinking copepod above copepod particles. Based on 50 m of sinking time above and mean residence Multi-decadal trends in oceanic biodiversity trends Multi-decadal At the ocean basin scale biodiversity of biodiversity basin scale the ocean At to is related copepods pelagic zooplankton over in warming and an increase temperature an by has been followed decades few the last link is also a direct There in diversity. increase of and the size-structure diversity between di The overall community. the zooplankton versity patterns of pelagic organisms, peaking of pelagic organisms, patterns versity north or south, 30° latitude 20° to between in the world’s gradients temperature follow a show phytoplankton oceans. Similarly, and temperature between relationship the phytoplank to is linked which diversity ton community having a higher diversity but a higher diversity having community ton and a more smaller size-fraction an overall (i.e. microbial- structure foodweb complex in production) -based based versus The environments. stratified more warmer, STATUS REPORT 6 Unusual biodiversity records tion). and the biodiversity of the North Atlantic (see trans-Arctic migra - larger consequences for theestablishment ofinvasive species the rapid climate change observed intheArctic may have even moving progressively poleward andinsomecases expanding, mentally unsuitable. Apartfrom limits thesethermalboundary establish viablepopulations inareas that were onceenviron species intheNorthSea)andinvasive speciesallowing themto for previously sub-tropical deniednon-indigenous species(e.g. Climate warming willopenupnew thermallydefined habitats other partsoftheworld. fisheries andthe general ecosystem whenithasappeared in because ofthevery marked impactitappears to have hadon even thoughithasnotyet beenrecorded intheBritishIsles, Mnemiopsis leidyi tail onplanktonic introductions. Thediscovery ofthe comb jelly Isles that includesplankton andHABspeciesprovides more de- A recent review ofnon-native marinespeciesaround theBritish of only30years. waters ofnorthernEurope andoutinto theAtlantic inamatter from itsfirst record offPlymouthin1977throughout all coastal and significant memberoftheplankton community, hasspread diatom Coscinodiscuswailesii on thespread ofnon-native plankton. For example, theinvasive frame, data from theCPRhave provided invaluable information Because ofitsextensive geographical coverage andlongtime this region. observations of a more southerly distribution, onlyahandful ofprevious 100 milesto thenorthwest ofScotland. Typically having the northernNorthSeain2009 aswell asapproximately commonly known thegoose barnacle,were observed in of cold water masses.Larvae ofthestalked barnacleLepas, in theNorthEast Atlantic andisthought to beanindicator in July2009.Usuallythisspeciesisfound muchfurthernorth protozoan, was recorded offthe north-west ofBrittany The tintinnid current. and itspresence may themovement signify oftheIrminger C. hexacanthum isrelatively rare intheNorth West Atlantic was onaSeptember route intheSouthWest Labrador Sea. only onerecord of in theNorthWest Atlantic. Contrastingly, in2009there was north-westerly distribution, withnumerous records found in 2008thisoceanicspeciesappeared to bespreading its samples; however throughout thesecond halfoftheyear East Atlantic. CPR records for thesespeciesever to befound intheNorth off thenorth-west coast ofScotland, thenorthern-most lamellicorne and UK. DuringMarch andSeptember 2009 Warm-water Ceratium isacommon phytoplankton taxa. Invasive species Ceratium were found unusuallycloseto the Parafavella gigantea, avase-shaped ciliated C. hexacanthum was alsofound onthese Lepas have been madeonCPRsamplesin C. pentagonum in NorthSeawaters isofparticular concern, C. hexacanthum found inthisregion, this , whichhasbecome apersistent were found 40-100miles C. arietinum, C. - Biology (2007)13:1910-1921 More information: present unknown. of suchachange to thefunctionandbiodiversity ofArctic systems are at inundation ofnew organisms to theNorth Atlantic. The consequences migration inmoderntimeswhich may bethe harbinger ofapotential The CPRsurvey hasdocumented thefirst evidence ofatrans-Arctic drawdown. suchassmaller-sizedservices fish communities and reduced carbon the community. Thisinturnmay have implications for marineecosystem Increasing biodiversity isassociated withadecreasing size-structure of between biodiversity andsize-structure inpelagiccommunities. associated withtemperature increases. There isastrong relationship Oceanic plankton biodiversity isincreasing intheNorthAtlantic Marine biodiversity andinvasive species policy makers forSummary 1910-1921 More information: GlobalChangeBiology(2007)13: are at present unknown. a change to thefunctionandbiodiversity ofArctic systems organisms to theNorthAtlantic. The consequences ofsuch and betheharbinger ofapotential inundation of new evidence ofatrans-Arctic migration inmoderntimes Atlantic for over 800,000 years and could bethefirst The diatom speciesitselfhasbeenabsent from theNorth 1990s whichhassincespread southwards andeastwards. Neodenticula seminae already documented thepresence ofaPacific diatom, migrations becoming a reality. The CPR survey has increasingly blurred withanincrease oftrans-Arctic the NorthAtlantic Oceanand Pacific may become a consequence thebiological boundariesbetween reducing faster thanprevious modelledestimates. As It hasrecently beenhighlighted that Arctic iceis Trans-Arctic migration PNAS(2010)107:10120-10124; Sir Alister Hardy Foundation for OceanScience , intheLabrador Seasincethelate Global Change STATUS REPORT 7 Microplastics Harmful Algal Blooms Algal Harmful The geographical distribution of some exceptional HABs in exceptional of some distribution The geographical of the bloom. the month indicate 2008. Numbers The geographical distribution of microplastics recorded on CPR recorded of microplastics distribution The geographical 2004-2007. While the distribution samples in 2008 and between that it does show CPR sampling frequency reflects largely including Atlantic in the North widely distributed are microplastics oceanic environment. the offshore - - - - - naturally forms forms naturally ). These results may may ). These results . Marine ecosystem and ecosystem Marine health environmental ). The incidence of monofilament ). The incidence of monofilament spp. numbers particularly for the particularly spp. numbers spp. that occurred in the southern occurred spp. that Noctiluca scintillans Noctiluca Sir Alister Hardy Foundation for Ocean Science Foundation Hardy Sir Alister Pseudo-nitchia Eutrophication and HABs Eutrophication Marine litter North Sea. extensive blooms during the summer period in these areas blooms during the summer period in these areas extensive HABs during 2008 occurred as in the Irish Sea. Large as well similar to and were variability of natural within the range the large However, occurrences. average the long-term blooms of also were in 2008 and particularly numerous North Sea were recorded February). 2008 also in early (starting exceptionally Dinophysis low exceptionally In general, HABs are naturally occurring events although some occurring events naturally HABs are In general, with eutrophication been associated blooms have exceptional along numerous most generally are HAB taxa waters. in coastal In particular the coast. and off the Danish coast the Dutch forming species red-tide mass (Phytoplankton Colour Index) over the last decade in cer decade the last over Colour Index) mass (Phytoplankton Sea, particu and North Atlantic of the North-East regions tain biomass phytoplankton Increased months. the winter larly over pat similar however, of eutrophication; be an indicator may (Limnology of nutrients concentrations lower utilise fectively (2007) 52: 635–648 and Oceanography be may transparency water variability and climatic that indicate to phytoplankton concentrations than nutrient important more influence overriding the in the North Sea. Despite production in some be of concern may levels nutrient elevated of climate, seas European around areas localised There has been a considerable increase in phytoplankton bio in phytoplankton increase a considerable has been There terns of change have been found in both coastal and offshore and offshore in both coastal been found have of change terns in phytoplankton increase In the North Sea a significant waters. anthropogenically- in both heavily biomass has been found less-affected and the comparatively waters coastal impacted in trends decreasing significantly open North Sea despite to be in biomass appears The increase concentrations. nutrient the waters that and evidence temperatures warmer to linked allowing (i.e. less turbid), thereby clearer also becoming are ef more to phytoplankton coastal the normally light-limited netting snagged by the CPR towed body also seems to be body also seems towed by the CPR snagged netting particularly in the southern North Sea. increasing, From the presence of microplastics recorded on CPR samples it recorded of microplastics the presence From in the North- widely distributed are microplastics is clear that the towards increasing with their frequency Atlantic East retrospective (particularly in the southern North Sea). From it decades of some CPR samples spannincg three analysis through in frequency increasing are microplastics that appears (2004) 308:834 time (Science Ocean acidification

Changes in temperature have direct consequences on many physiological processes (e.g. oxygen metabolism, adult mortality, reproduction, respiration, reproductive Ocean acidification development) and control virtually all life-processes from the molecular to the cellular and from the regional 10 ecosystem level to biogeographical provinces. Temperature

also modulates species interactions (e.g. competition, prey- 8 predator interactions and foodweb structures) both directly and indirectly; ultimately, changes in temperatures caused )

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by climate change can lead to impacts on the biodiversity, y c n

size structure, carrying capacity and functioning of the e u q e

whole pelagic ecosystem. While temperature has direct r

F 4 consequences on many biological and ecological traits it also modifies the marine environment by influencing oceanic circulation and by enhancing the stability of the 2 water column and hence nutrient availability. Under many climate change scenarios, oceanic primary production is predicted to decline due to nutrient limitation. 0 1958 1963 1968 1973 1978 1983 1988 1993 1998 2003 2008 Year While temperature, light and nutrients are probably the The percent frequency of foraminifera recorded on CPR most important physical variables structuring marine samples ecosystems, the pelagic realm will also have to contend with, apart from global climate warming, the impact associated with climate shifts in the Northern Hemisphere temperature (see above figure of foraminifera frequency). of anthropogenic CO2 directly influencing the pH of the oceans. Evidence collected and modelled to date indicates However, there is some observed evidence from the Southern Ocean that modern shell weights of foraminifera that rising CO2 has led to chemical changes in the ocean which has led to the oceans becoming more acidic. Ocean have decreased compared with much older sediment acidification has the potential to affect the process of core records with acidification being implicated (Nature calcification and therefore certain planktonic organisms (e.g. Geoscience (2009) doi:10.1038/ngeo460). It is not yet coccolithophores, foraminifera, pelagic molluscs) may be known how much of an effect acidification will have on the biology of the oceans in the 21st century, whether rapid particularlyTrans-Arctic vulnerable to future CO2 emissions. migration Apart from climate warming, potential chemical changes to the oceans climate warming will override the acidification problem, and and their effect on the biology of the oceans could further whether or not species can buffer the effects of acidification through adaptation. The CPR survey is providing a reduce the ocean’s ability to absorb additional CO2 from the atmosphere, which in turn could affect the rate and scale of critical baseline (both in space and time) and is currently climate warming. monitoring these vulnerable organisms in case in the future these organisms begin to show negative effects due to Presently in the North Atlantic certain calcareous taxa acidification. are actually increasing in terms of abundance, a trend

Summary for policy makers

Marine ecosystem health At the regional scale, it has been found that most phytoplankton trends are related to hydro-climatic variability as opposed to anthropogenic input (e.g. nutrient input leading to eutrophication). This means that the North-East Author for correspondence: Atlantic as a whole is generally not considered to be eutrophic. This is not to email [email protected] say, however, that certain coastal areas and the southern North Sea are not vulnerable to eutrophication and climate change may also exacerbate these SAHFOS negative effects in these vulnerable regions. The Laboratory It has also been found that the number of microplastics collected on CPR Citadel Hill samples is increasing and the frequency of occurrence. Bloom timing of Plymouth some species are related to regional climate warming. UK The plankton community is continuing to evolve in time with large changes (regime shifts) occurring in the late 1980s and in 2000 in response to regional climate warming. The ecosystem is therefore not temporally stable. Similarly, higher trophic levels (e.g. fish, seabirds) are also changing. More information: Limnology and Oceanography (2007) 51: 820-829; Science (2004) 308:834