Connecting the Dots: Responses of Coastal Ecosystems to Changing Nutrient Concentrations

Empirical relationships between phytoplankton biomass and nutrient concentrations established across a wide range of different ecosystems constitute fundamental quantitative tools for predicting effects of nutrient management plans. Nutrient management plans based on such relationships, mostly established over trends of increasing rather than decreasing nutrient concentrations, assume full reversibility of coastal eutrophication. Monitoring data from 28 ecosystems located in four well-studied regions were analyzed to study the generality of chlorophyll a versus nutrient relationships and their applicability for ecosystem management. We demonstrate significant differences across regions as well as between specific coastal ecosystems within regions in the response of chlorophyll a to changing nitrogen concentrations. We also show that the chlorophyll a versus nitrogen relationships over time constitute convoluted trajectories rather than simple unique relationships. The ratio of chlorophyll a to total nitrogen almost doubled over the last 30-40 years across all regions. The uniformity of these trends, or shifting baselines, suggest they may result from large-scale changes, possibly associated with global climate change and increasing human stress on coastal ecosystems. Ecosystem management must, therefore, develop adaptation strategies to face shifting baselines and maintain ecosystem services at a sustainable level rather than striving to restore an ecosystem state of the past. © 2011 American Chemical Society.This research is a contribution to the Thresholds Integrated Project (contract FP6-003933-2) and WISER (contract FP7-226273), funded by the European Commission.Peer Reviewe

Gracilaria vermiculophylla (Ohmi) Papenfuss, 1967 (Rhodophyta, Gracilariaceae) in northern Europe, with emphasis on Danish conditions, and what to expect in the future

Gracilaria vermiculophylla, a red macroalga from the West Pacific, was discovered in western Germany (the Wadden Sea) in 2002 and has since also been observed in Sweden (from about 70 km south to about 80 km north of Göteborg), Denmark (Wadden Sea, Horsens Fjord, Limfjorden, Vejle Fjord, Holckenhavn Fjord, Øster Hurup Harbor) and eastern Germany (Kiel Bay). Today, less than 5 years following its first observation in the Wadden Sea the invader is common in many invaded regions, often being amongst the most abundant macroalgal species. G. vermiculophylla is successful in shallow protected soft-bottom estuaries and bays, typically in association with ubiquitous native invertebrates (lugworms, tube-building worms, mussels, cockles, snails). The invertebrates provide substratum for holdfast attachment and thalli incorporation, most likely increasing the stability of local G. vermiculophylla populations. We hypothesize that this substratum provision is highly important for its general invasion success. We also confirm that G. vermiculophylla can maintain growth at all salinities experienced along Danish coastlines (8.5-34 psu). In addition, laboratory experiments indicate that the ubiquitous grazer Littorina littorea has the potential to control G. vermiculophylla growth under specific environmental conditions, but also that L. littorea may facilitate small-scale dispersal within invaded locations, because grazing increases thalli fragmentation rates. Given its widespread distribution, rapid range expansion, and known ecological traits, G. vermiculophylla is clearly a permanent resident of northern European waters

Sediment inorganic carbon (PIC) deposits in seagrass meadows and adjacent sand-patches (v. 2)

The database compiles published and unpublished data on carbonate (CaCO3) and/or particulate inorganic carbon (PIC) along with particulate organic carbon (POC) stocks if available, in sediments of seagrass meadows and adjacent un-vegetated patches. We considered the total pool of CaCO3 reported without distinguishing between the different biogenic carbonate mineral forms (calcite, Mg-calcite and aragonite). Fourqurean et al. (2012) provided data for 201 sites, and a literature search using both the Web of Knowledge (using the search terms “seagrass*” AND “inorganic carbon*” AND [“calcific* OR sediment* OR CaCO3 OR dissolut* OR diagenesis”]) and Google Scholar (using the search terms “seagrass carbonate”) yielded data for an additional 82 sites. The database was amended with unpublished values for 154 additional sites sampled by the authors. The database compiles data on sediment carbonate concentration for a total of 437 sites, of which 34 corresponded to sand patches adjacent to seagrass meadows. The final database comprises estimates for 403 seagrass vegetated sites, including 219 estimates for sediment surface samples (ca. 1-30 cm depth) and 184 estimates for sediment cores of variable length (149 cores < 100 cm-long, and 35 cores ≥ 100 cm-long). When only one of the variables, CaCO3 or PIC was reported, the other was estimated assuming that PIC is 12% of the total molar mass of the CaCO3. In most cases, particulate inorganic and organic carbon (PIC and POC) were reported as a percentage of dry weight (%DW), where PIC and POC, in mg cm-3, was calculated as the product of the fraction of sediment dry weight composed by PIC or POC and the dry bulk density (DBD) of a given sediment section (n = 340 sites). When DBD was not reported (n = 113 sites), we used the average DBD (1.03 g cm-3) reported by Fourqurean et al. (2012) for seagrass sediments in the calculations. Enquiries about the dabaset may be sent to Inés Mazarrasa .[Access and reuse conditions] This database and its components are subject to a Creative Commons Attribution-Noncommercial-ShareAlike International licence 4.0.[Reason for updating the database] This database is a corrected version of the database by Mazarrasa et al., (2015) (DIGITAL.CSIC, http://hdl.handle.net/10261/116550). In the previous version of the database, CaCO3 and PIC values for 3 sediment cores from Oyster Harbour, Western Australia (cores # 275-277) and from 13 cores from Greenland and Denmark (cores # 391-403) were wrong. In this new version of the database these errors have been corrected. In addition, we have added data of 35 sediment slices of the cores from Greenland (cores # 391-397) that were missing in the previous version of the database. These changes do not significantly affect the results presented in the paper published in Biogeoscience (Mazarrasa et al., 2015) that was produced using the previous version of the database.The database is a global compilation of published and unpublished data available on carbonate (CaCO3), particulate inorganic carbon (PIC) and particulate organic carbon (POC) stocks in sediments of seagrass meadows and adjacent un-vegetated sediments.N

Sediment inorganic carbon (PIC) deposits in seagrass meadows and adjacent sand-patches

The database compiles published and unpublished data on carbonate (CaCO3) and/or particulate inorganic carbon (PIC) along with particulate organic carbon (POC) stocks if available, in sediments of seagrass meadows and adjacent un-vegetated patches. We considered the total pool of CaCO3 reported without distinguishing between the different biogenic carbonate mineral forms (calcite, Mg-calcite and aragonite). Fourqurean et al. (2012) provided data for 201 sites, and a literature search using both the Web of Knowledge (using the search terms “seagrass*” AND “inorganic carbon*” AND [“calcific* OR sediment* OR CaCO3 OR dissolut* OR diagenesis”]) and Google Scholar (using the search terms “seagrass carbonate”) yielded data for an additional 82 sites. The database was amended with unpublished values for 154 additional sites sampled by the authors. The database compiles data on sediment carbonate concentration for a total of 437 sites, of which 34 corresponded to sand patches adjacent to seagrass meadows. The final database comprises estimates for 403 seagrass vegetated sites, including 219 estimates for sediment surface samples (ca. 1-30 cm depth) and 184 estimates for sediment cores of variable length (149 cores < 100 cm-long, and 35 cores ≥ 100 cm-long). When only one of the variables, CaCO3 or PIC was reported, the other was estimated assuming that PIC is 12% of the total molar mass of the CaCO3. In most cases, particulate inorganic and organic carbon (PIC and POC) were reported as a percentage of dry weight (%DW), where PIC and POC, in mg cm-3, was calculated as the product of the fraction of sediment dry weight composed by PIC or POC and the dry bulk density (DBD) of a given sediment section (n = 340 sites). When DBD was not reported (n = 113 sites), we used the average DBD (1.03 g cm-3) reported by Fourqurean et al. (2012) for seagrass sediments in the calculations. Enquiries about the dabaset may be sent to Inés Mazarrasa .Access and reuse conditions: This database and its components are subject to a Creative Commons Attribution-Noncommercial-ShareAlike International licence 4.0.Mazarrasa, Inés; Marbà, Núria; Lovelock, Catherine E.; Serrano, Oscar; Lavery, Paul S.; Fourqurean, James W.; Kennedy, Hillary; Mateo, Miguel Ángel; Krause-Jensen, Dorte; Steven, Andy D. L.; Duarte, Carlos M., "Sediment inorganic carbon (PIC) deposits in seagrass meadows and adjacent sand-patches (v. 2)". 2018, DIGITAL.CSIC, http://dxThe database is a global compilation of published and unpublished data available on carbonate, particulate inorganic carbon (PIC) and particulate organic carbon (POC) stocks in sediments of seagrass meadows and adjacent un-vegetated sediments.Peer reviewe