Nutrient reduction and the improvement of bottom water oxygen concentrations are thought to be key factors in the recovery of eutrophic aquatic ecosystems. The effects of reoxygenation and bioturbation of natural hypoxic sediments in the Baltic Sea were studied using a mesocosm experiment. Anoxic sediment box cores were collected from 100 m depth in Kanholmsfjärden (Stockholm Archipelago) and maintained in flow-through mesocosms with 3 treatments: (1) hypoxic: supplied with hypoxic water; (2) normoxic: supplied with oxic water; and (3) Marenzelleria: supplied with oxic water and the polychaete Marenzelleria spp. (2000 ind. m^–2). After a 7 wk long conditioning period, net fluxes of dissolved O₂, CH₄, Fe²⁺, Mn²⁺, NH₄⁺, NO₂^-, NO₃^-, PO₄^3- and H₄SiO₄, and rates of nitrate ammonification (DNRA), denitrification and anammox were determined. Phosphate was taken up by the sediment in all treatments, and the uptake was highest in the normoxic treatment with Marenzelleria. Normoxic conditions stimulated the denitrification rate by a factor of 5. Denitrification efficiency was highest under normoxia (50%), intermediate in bioturbated sediments (16%), and very low in hypoxic sediments (4%). The shift from hypoxic to normoxic conditions resulted in a significantly higher retention of NH₄⁺, H₄SiO₄ and Mn²⁺ in the sediment, but the bioturbation by Marenzelleria reversed this effect. Results from our study suggest that bioturbation by Marenzelleria stimulates the exchange of solutes between sediment and bottom water through irrigation and enhances bacterial sulfate reduction in the burrow walls. The latter may have a toxic effect on nitrifying bacteria, which, in turn, suppresses denitrification rates.

Sediments underlying hypoxic or anoxic water bodies constitute a net source of phosphorus to the bottom water. This source has the potential to enhance eutrophication. Benthic fluxes of dissolved phosphorus, iron and manganese were measured from hypoxic, normoxic, and normoxic bioturbated by the invasive polychaete Marenzelleria arctia sediment in a mesocosm experiment. The highest benthic phosphorus efflux was detected in mesocosms with the hypoxic treatment. Normoxic, bioturbated sediments led to weaker retention of phosphorus compared to oxic, defaunated sediments. Both iron and manganese fluxes increased under bioturbated conditions compared to defaunated sediments. This study shows that re-oxygenation of previously anoxic coastal sediments enhance phosphorus retention in the sediments. Colonisation by M. arctia induce strong mobilisation of iron and manganese due to its intense bioirrigation, which facilitates organic matter degradation and decreases the phosphorus retention by metal oxides in sediment.

Seabirds redistribute nutrients between different ecosystem compartments and over vast geographical areas. This nutrient transfer may impact both local ecosystems on seabird breeding islands and regional biogeochemical cycling, but these processes are seldom considered in local conservation plans or biogeochemical models. The island of Stora Karlsö in the Baltic Sea hosts the largest concentration of piscivorous seabirds in the region, and also hosts a large colony of insectivorous House martins Delichon urbicum adjacent to the breeding seabirds. We show that a previously reported unusually high insectivore abundance was explained by large amounts of chironomids—highly enriched in δ¹⁵N—that feed on seabird residues as larvae along rocky shores to eventually emerge as flying adults. Benthic ammonium and phosphate fluxes were up to 163% and 153% higher close to the colony (1,300 m distance) than further away (2,700 m) and the estimated nutrient release from the seabirds at were in the same order of magnitude as the loads from the largest waste-water treatment plants in the region. The trophic cascade impacting insectivorous passerines and the substantial redistribution of nutrients suggest that seabird nutrient transfer should be increasingly considered in local conservation plans and regional nutrient cycling models.

High intensity agricultural production systems are problematic not only for human health and the surrounding environment, but can threaten the provision of ecosystem services on which farm productivity depends. This research investigates the effects of management practices in Costa Rica on on-farm insect diversity, using three different types of banana farm management systems: high-input conventional system, low-input conventional system, and organic system. Insect sampling was done using pitfall and yellow bowl traps, left for a 24-h period at two locations inside the banana farm, at the edge of the farm, and in adjacent forest. All 39,091 individual insects were classified to family level and then morphospecies. Insect species community composition and diversity were compared using multivariate statistics with ordination analysis and Monte Carlo permutation testing, and revealed that each of the management systems were significantly different from each other for both trap types. Insect diversity decreased as management intensity increased. Reduced insect diversity resulted in fewer functional groups and fewer insect families assuming different functions essential to ecosystem health. Organic farms had similar species composition on the farm compared to adjacent forest sites, whereas species composition increasingly differed between farm and forest sites as management intensity increased. We conclude that while organic production has minimal impact on insect biodiversity, even small reductions in management intensity can have a significantly positive impact on on-farm insect biodiversity and functional roles supported.

Export banana production in Latin America is pesticide intensive, receiving much negative publicity regarding human health problems and environmental degradation. The Rainforest Alliance (RA) certification scheme was established to certify farms that met a number of social, occupation health and environmental standards set by RA and their certifying body, the Sustainable Agriculture Network (SAN). This study was one of the first, independent studies of the environmental impact of some of the principles set by RA and SAN. The study focuses on insect and bird diversity as an indicator of ecosystem health. Five RA certified farms, six non-RA certified farms, and five organic certified farms were sampled. The data was analyzed with RDA multivariate analyses and Monte Carlo permutation tests. The results showed that RA certified farms had less insect diversity compared to non-RA certified farms and that both farm types had less insect diversity than organic farms. There was little difference between RA and non-RA certified farms with regards bird community composition. Thus, organic farming conserves biodiversity, while alternative environmental labels (e.g. a Rainforest alliance seal) may not have any visible positive effect on in-farm biodiversity. This study points to the need for improvements in SAN certification standards to achieve improved environmental conditions.

Denna rapport presenterar resultaten av 2011 års undersökning av mjukbottenfaunan i Östergötlands skärgård. Undersökningen är en del av det regionalt-nationellt samordnade miljöövervakningsprogrammet som startade år 2007. 20 stationer belägna på djup mellan 10 och 38 meter undersöks årligen avseende bottenfauna och sedimentkvalité. Av dessa 20 stationer ligger hälften i S:t Annas skärgård (kluster REG St Anna) och hälften i Gryts skärgård (kluster REG Gryt) (Fig. 1). Stationerna är belägna i 5 olika vattenförekomster enligt SMHI:s indelning. Av stationerna i S:t Annas skärgård ligger 9 st i vattenförkomsten Kärrfjärden, medan 1 station ligger i Finnfjärden. Av stationerna i Gryts skärgård ligger 5 st i Hesselöfjärden, 3 st i Orren och 2 st i Ytteröområdet. Två stationer har provtagits tidigare på uppdrag av Motala Ströms Vattenvårdsförbund (Stn Bf 34b och stn Bf 32). Data från dessa redovisas även separat för att illustrera långtidsförändringar.

Huvudfokus för undersökningen är statusbedömning av bottensamhället med hjälp av Benthic Quality Index (BQI). Statusen för klustret REG St Anna bedöms år 2011 som måttlig efter tre år med god status. I klustret REG Gryt bedöms statusen alltjämt som god. År 2011 beräknades BQI-värdet (20:e percentilen) för klustret REG St Anna till 3,6. Detta är en försämring sedan 2010 (20:e percentilen av BQI=4,5) men värdet är högre än det som noterades för 2007 (2,8), dvs vid programmets start. I klustret REG Gryt har BQI-värdet ökat från 5,9 till 6,2 sen förra året. Vid en jämförelse med värdet för 2007 har områdets BQI-värde minskat från ett mycket högt BQI-värde på 8,2.

Den biologiska mångfalden, uttryckt som totalt antal taxa, har minskat något sedan föregående år inom båda klustren. Medelantalet taxa har också minskat i REG St Anna, medan en svag ökning kan noteras för REG Gryt. Just det minskade antalet taxa i REG St Anna utgör den största orsaken till områdets lägre BQI-värde. De taxa som försvunnit har tidigare endast förekommit med ett fåtal individ och på enstaka stationer. Den största förändringen i bottenfaunasammansättningen sedan förra året är en markant ökning av den för Östersjön relativt nya havsborstmasken Marenzelleria spp. i REG Gryt.

Sammanfattningsvis har statusen försämrats till måttlig i REG St Anna men i REG Gryt är statusen fortsatt god.

Denna rapport redovisar resultaten av 2011 års undersökning av mjukbottenfaunan i Askö-Landsortsområdet. 20 stationer belägna på djup mellan 9 och 60 meter undersöks årligenavseende bottenfauna och sedimentkvalité. Undersökningen är en del av det regionalt-nationelltsamordnade miljöövervakningsprogrammet som startade år 2007. Stationerna ingick mellan 1981 och 2006 i den nationella miljöövervakningen. Fyra av dem har besökts varje år sedan 1970-talet inom tidigare forskningsprojekt, och långtidsförändringar för dessa redovisas separat.

Huvudfokus för undersökningen är statusbedömning av bottensamhället med hjälp av Benthic Quality Index (BQI). Statusen för Asköområdet har minskat signifikant sedan 1970-talet. Denna minskning beror huvudsakligen på ett skifte från ett bottensamhälle dominerat av vitmärlorna Monoporeia affinis och Pontoporeia femorata till ett dominerat av östersjömusslan Macoma balthica. Sedan mitten av 2000-talet förekommer nu också ett för Östersjön nytt släkte av havsbortmaskar Marenzelleria spp. Både östersjömusslan och den introducerade havsbortsmasken Marenzelleria spp. är tåligare mot låga syrehalter än vitmärlorna och har lägrekänslighetsvärden i BQI-indexet. Detta ger området en lägre status än vid mätningarna under 1970- och början av 1980-talet.

År 2011 beräknades BQI-värdet (20:e percentilen) för området till 5,8, en försämring sedan 2010 (20:e percentilen av BQI=6,8). Vid en jämförelse över längre tid har områdets BQI-värdenminskat. Den nedåtgående trenden förefaller emellertid ha brutits och från 2001 kan ensignifikant ökning av BQI observeras. Den biologiska mångfalden, uttryckt som antal taxa, följer samma mönster som BQI, med enuppgång sedan 2001. En del av förklaringen till den ökade biologiska mångfalden beror påförekomsten av havsborstmasken Marenzelleria spp. Uppmätta värden av bottenfaunans biomassa ligger nu på ungefär samma nivå som på 1980-talet, efter att under perioden 1996 till2006 ha legat på en högre nivå.

Sammanfattningsvis visar 2011 års undersökning att miljötillståndet för Asköområdets mjukabottnar förbättrats sedan programmets början 2007, och att den ekologiska statusen har ökat signifikant sedan 2001.

In Costa Rica, considerable effort goes to conservation and protection of biodiversity, while at the same time agricultural pesticide use is among the highest in the world. Several protected areas, some being wetlands or marine reserves, are situated downstream large-scale banana farms, with an average of 57 pesticide applications per year. The banana industry is increasingly aware of the need to reduce their negative environmental impact, but few ecological field studies have been made to evaluate the efficiency of proposed mitigation strategies. This study compared the composition of benthic macroinvertebrate communities up- and downstream effluent water from banana farms in order to assess whether benthic invertebrate community structure can be used to detect environmental impact of banana fanning, and thereby usable to assess improvements in management practises. Aquatic invertebrate samples were collected at 13 sites, using kick-net sampling. both up- and downstream banana farms in fast flowing streams in the Caribbean zone of Costa Rica. In total, 2888 invertebrate specimens were collected, belonging to 15 orders and 48 families or taxa. The change in community composition was analysed using multivariate statistics. Additionally, a biodiversity index and the Biological Monitoring Working Party (BMWP) score system was applied along with a number of community composition descriptors. Multivariate analyses indicated that surface waters immediately up- and downstream large-scale banana farms have different macroinvertebrate community compositions with the most evident differences being higher dominance by a single taxa and a much higher total abundance, mostly of that same taxon. Assessment of macroinvertebrate community composition thus appears to be a viable approach to detect negative impact from chemical-intensive agriculture and could become an effective means to monitor the efficacy of changes/proposed improvements in fanning practises in Costa Rica and similar systems.