Land Ocean Interactions In The Coastal Zone Research Articles

Dissolved Inorganic Nutrient Biogeochemistry in an Urbanized Coastal Region: A Study of Dapeng Cove, Shenzhen

Dissolved inorganic nutrients are pivotal in maintaining the material and energy balance of marine ecosystems, impacting the survival and dynamic succession of marine organisms. To gain a deeper understanding of the source and sink characteristics of dissolved inorganic nutrients in bays affected by human activities and to elucidate the processes involving filter-feeding shellfish in relation to these nutrients, this study investigated the source and sink dynamics of dissolved inorganic nutrients in the Dapeng Cove sea area of Shenzhen. Over the past decade, a significant change in the N/P ratio within the survey area has been observed, suggesting a shift in nutrient limitation from nitrogen to phosphorus or phosphorus–silicon limitation. This induced change in the N/P ratio, along with Si/N and Si/P ratios, may facilitate the growth of cyanobacteria and, subsequently, alter the proportions of diatoms, dinoflagellates, and cyanobacteria. Seasonal fluctuations in human disturbance intensity and precipitation determine the seasonal and spatial distribution of nutrients in the bay, thereby influencing the bay ecosystem metabolism. The Land–Ocean Interactions in the Coastal Zone (LOICZ) model analysis revealed that the bay represents a major source of inorganic nitrogen and a source of phosphate in spring, summer, and autumn, while acting as a sink for phosphate in winter. Furthermore, rivers and groundwater represent the primary sources of phosphate and inorganic nitrogen in the bay. The bay exhibits an annual net ecosystem metabolic rate of 7.06 mmol C/m2/d, with denitrification dominating the nitrogen cycle at 12.65 mmol C/m2/d. Overall, the Dapeng Cove ecosystem displays net production exceeding respiration, classifying it as an autotrophic system. Additionally, the nitrogen cycle in the sea area is predominantly driven by denitrification. The analysis also revealed that the impact of oyster proliferation on the physical and chemical factors in the surveyed area is relatively weaker than that of surface runoff and groundwater inputs.

Sources and long-term variation characteristics of dissolved nutrients in Maowei Sea, Beibu Gulf, China

Sources and long-term variation characteristics of dissolved nutrients in Maowei Sea, Beibu Gulf, China

Biogeochemical Budgets of Nutrients and Metabolism in the Curonian Lagoon (South East Baltic Sea): Spatial and Temporal Variations

Estuaries are biogeochemical reactors able to modulate the transfer of energy and matter from the watershed to the coastal zones and to retain or remove large amounts of terrestrially generated nutrients. However, they may switch from nutrient sink to source depending upon interannual variability of the nutrient supply and internal processes driving whole system metabolism (e.g., net autotrophic or heterotrophic). We tested this hypothesis in the Curonian Lagoon, a hypertrophic estuary located in the south east Baltic Sea, following the budget approach developed in the Land-Ocean Interactions in the Coastal Zone (LOICZ) project. Annual budgets for nitrogen (N), phosphorus (P), and silica (Si) were calculated for the 2013–2015 period. The lagoon was divided in a flushed, nutrient loaded area, and in a confined, less loaded area. The lagoon was always a sink for dissolved inorganic Si and P whereas it was a N sink in the confined area, dominated by denitrification, and a N source in the flushed area, due to dinitrogen (N2) fixation. The net ecosystem metabolism (NEM) indicated that the Curonian Lagoon was mainly autotrophic because of high primary production rates. In this turbid system, low N:P ratio, high summer temperatures, and calm weather conditions support high production of N2-fixing cyanobacteria, suppressing the estuarine N-sink role.

Internal nutrient loading is a potential source of eutrophication in Shenzhen Bay, China

As a highly eutrophic area, Shenzhen Bay in southern China has accumulated plant dissolved inorganic nitrogen (DIN) and phosphate (PO43--P), resulting in various environmental problems. The nutrient loading was calculated to classify runoff patterns of the bay and provide possible management solutions. However, previous studies have shown that external loading alone cannot explain the source of nutrition in Shenzhen Bay. In our study, for the first time, we proved quantitatively that internal nutrient loading was the main contributor of the total input fluxes of dissolved DIN and PO43--P in Shenzhen Bay using the LOICZ (land–ocean interactions in the coastal zone) model. Our results showed that the internal loading supplied 65 and 69% of total input fluxes of dissolved DIN and PO43--P, which were c. 4.0 × 106 and 0.3 × 106 mol/d, respectively. The estimated nutrient input flux from terrigenous loading were c. 1.38 × 106 and 0.1 × 106 mol/d of DIN and PO43--P, respectively. Notably, the internal loading from sediment resuspension supplied c. 3.5–15.7 × 106 and 0.5–1.9 × 106 mol/d of particle nitrogen and bioavailable phosphate to Shenzhen Bay, respectively. Moreover, 51 and 62% of DIN and PO43--P were exported through water exchange and residual flows from Shenzhen Bay into the Pearl River. These results demonstrate that internal loading dynamics and nutrient losses to the Pearl River jointly influence the eutrophication process in Shenzhen Bay.

Coupled effects of anthropogenic nutrient sources and meteo-oceanographic events in the trophic state of a subtropical estuarine system

Coupled effects of anthropogenic nutrient sources and meteo-oceanographic events in the trophic state of a subtropical estuarine system

Implications of poor-regulated wastewater treatment systems in the water quality and nutrient fluxes of a subtropical coastal lagoon

Implications of poor-regulated wastewater treatment systems in the water quality and nutrient fluxes of a subtropical coastal lagoon

Trophic dynamics (Dissolved Inorganic Nitrogen-DIN and Dissolved Inorganic Phosphorus-DIP) in tropical urban estuarine systems during periods of high and low river discharge rates.

This paper focused on the use of the biogeochemical LOICZ (Land Ocean Interactions in the Coastal Zone) to investigate the dynamics of DIN and DIP nutrients among three highly urbanized tropical estuaries (Barra das Jangadas (BJ), Recife (RE) and Timbó (TB)), located in the northeastern region of Brazil. The input data were obtained through in situ measurements (2007) and governmental agency databases (2001-2007). The balances of the non-conservative elements showed that the RE and TB systems alternated between sources and sinks during the observation periods (0.2-0.8 mmoles DIP m-2 d-1 and 0.1-10 mmoles DIN m-2 d-1). The metabolism rates in the systems indicated that the BJ system was autotrophic during the two observation periods (10-26 mmoles C m-2 d-1), while the RE system was heterotrophic (9-12 mmoles C m-2 d-1). The river discharge rates observed during the period 2001-2007 showed averages ranging from 9.4±3.8 to 18.4±7.7 m3s-1. Measurements of the trophic status in the RE system during 2007 characterized the system as eutrophic, thereby demonstrating high levels of chlorophyll-a and inorganic nutrients. The applications of balance sheets modeling proved to be very useful toward understanding the dynamics of estuarine systems dominated by large urban centers.

Nutrient budgets in the Piratininga-Itaipu lagoon system (southeastern Brazil): effects of sea-exchange management

The Piratininga-Itaipu Lagoon System and its drainage basin, located on the southeastern coast of Brazil, Niterói (RJ), has been the target of an intense process of urbanization over the last four decades. As a result of this process, both the lagoon and the adjacent sea area have shown signs of eutrophication due to the release of large quantities of domestic sewage semi (or not) treated. In an attempt to minimize these effects, in 2008 the government re-established a connection between the Piratininga lagoon and the sea. To evaluate changes and variations in the balance of dissolved inorganic nutrients, before and after interventions, the geochemical model of two stoichiometric mass balance boxes of the "LOICZ Program” (Land-Ocean Interactions in the Coastal Zone) was used. The salt and water balance showed different water residence times in the Piratininga lagoon for the two periods: 2005-2006 (before the opening of the connection between the Piratininga lagoon and the sea) and 2009-2010 (after the opening of the connection with the sea). The first period showed a value about two times higher than that obtained for 2009-2010, τ = 83 and 39 days respectively. The water residence time of the Itaipu lagoon did not show great variations between the two periods (τ = 9 and 8 days). For the period of 2005-2006, before the opening of the connection with the sea, both the lagoons were autotrophic (∆DIP > 0) and nitrogen loss was predominant (∆DIN < 0). The second period (2009-2010) was characterized by changes only in the trophic state of the Piratininga lagoon, which became heterotrophic (∆DIP > 0).

Balanço de Massa para Nutrientes Inorgânicos (N e P) no Estuário do Rio Itajaí-Açu, SC

This work aimed to determine the dissolved inorganic nutrient flows and calculate a budget for N and P in the Itajai-Acu River Estuary, SC, Brazil. Flows were calculated according to the method developed by LOICZ (Land Ocean Interactions in the Coastal Zone), based on the balance of water, salt and N and P in the estuary. Data were collected weekly at seven sampling sites between 2003 and 2004 and the balances were calculated for the lowest and highest period of the river discharge (97 and 228 m3.s-1). The results showed a hydraulic residence time ranging between 12.4 h and 23 h for the surface layer of the system and between 58 h and 65 h for the bottom layer. The estuary was a sink for phosphate, removing 50% of the computed entries and this was attributed to adsorption to suspended particulate material, since the primary productivity is low. The estuary showed no conservative increase of ammonia and nitrite, related to mineralization and nitrification of organic matter, and low variation for nitrate. The sewage was shown to be an important component of the flows, accounting for 28-42% of P inputs and 23-30% of N inputs to the estuary.

Land–Ocean Interactions in the Coastal Zone: Past, present & future

Land–Ocean Interactions in the Coastal Zone: Past, present & future

Regional initiatives for interlinking global coastal scientific research projects

Regional initiatives for interlinking global coastal scientific research projects

The State of Rhode Island's pioneering marine spatial plan

The State of Rhode Island's pioneering marine spatial plan

Seasonal dissolved inorganic nitrogen and phosphorus budgets for two sub-tropical estuaries in south Florida, USA

Abstract. Interactions among geomorphology, circulation, and biogeochemical cycling determine estuary responses to external nutrient loading. In order to better manage watershed nutrient inputs, the goal of this study was to develop seasonal dissolved inorganic nitrogen (DIN) and phosphorus (DIP) budgets for the two estuaries in south Florida, the Caloosahatchee River estuary (CRE) and the St. Lucie Estuary (SLE), from 2002 to 2008. The Land–Ocean Interactions in the Coastal Zone (LOICZ) approach was used to generate water, salt, and DIN and DIP budgets. Results suggested that internal DIN production increases with increased DIN loading to the CRE in the wet season. There were hydrodynamic effects as water column concentrations and ecosystem nutrient processing stabilized in both estuaries as flushing time increased to >10 d. The CRE demonstrated heterotrophy (net ecosystem metabolism or NEM < 0.0) across all wet and dry season budgets. While the SLE was sensitive to DIN loading, system autotrophy (NEM > 0.0) increased significantly with external DIP loading. This included DIP consumption and a bloom of a cyanobacterium (Microcystis aeruginosa) following hurricane-induced discharge to the SLE in 2005. Additionally, while denitrification provided a microbially-mediated N loss pathway for the CRE, this potential was not evident for the SLE where N2 fixation was favored. Disparities between total and inorganic loading ratios suggested that the role of dissolved organic nitrogen (DON) should be assessed for both estuaries. Nutrient budgets indicated that net internal production or consumption of DIN and DIP fluctuated with inter- and intra-annual variations in freshwater inflow, hydrodynamic flushing, and primary production. The results of this study should be included in watershed management plans in order to maintain favorable conditions of external loading relative to internal material cycling in both dry and wet seasons.

A Systems Approach for Sustainable Development in Coastal Zones

This Special Feature of Ecology and Society brings together important outcomes of the EU-funded project: Science-Policy Integration for Coastal System Assessment, SPICOSA. The title of the project revealed its innovative nature from the start. The premise was to bind scientific information to policy decisions and to consider the coastal zone as an integrated ecological-social-economic system. As a result, the SPICOSA project was very broad, ambitious, and required multidisciplinary teams of researchers to work together: natural scientists such as oceanographers and ecologists, social scientists, economists, and modelers. In itself, this was a tour de force. In addition, the project required a participatory role from stakeholders or actors, e.g., institutions, NGOs, economic sectors, etc., as well as from coastal managers and decision makers. SPICOSA is relevant to several facets of environmental policy such as the Water Framework Directive, the Marine Strategy Framework Directive, the Habitat Directive, and NATURA2000, as well as the ICZM-Integrated Coastal Zone Management recommendation. The primary objective of the project was to develop a practical application of the Systems Approach Framework (SAF), which represents an important step forward to enable the appropriate implementation of these policies. The SAF was applied at 18 study sites, representing a wide variety of European coastal systems, including transitional waters such as lagoons, deltas, and estuaries, along the coasts of the European regional seas, from the shores of the Black Sea to the fjords of Norway. The SAF addresses the general problem of assessing complex systems for conversion to sustainable development and thereby makes a valuable contribution to sustainability science. This contribution is not just at an academic level, because it has been demonstrated to be fully operational for European coastal systems, despite the wide range of governance that these systems encompass. Although the SPICOSA sites are European, the widespread applicability of the SAF makes it relevant at the global scale. As such, SPICOSA was recognized by Land-Ocean Interactions in the Coastal Zone as one of the truly integrative projects joining social and ecological aspects of coastal systems and with the SAF representing a major advance in the use of the system approach in coastal zones.

On the critical issues of land-ocean interactions in coastal zones

Land-ocean interactions in coastal zones comprise a broad research topic in global change science that links the fundamental questions of marine sciences to the sustainability of socio-economics. In the present study, critical issues in land-ocean interactions were addressed based on recent research progress and a literature review. Specifically, the exchange between open boundary and coastal systems, loss of chemical elements from watersheds, coastal eutrophication and harmful algal blooms, hypoxia and dead zones, source vs sink of sediments in coastal environments, feedback to other compartments of the Earth system, sea level rise and its impact on economics and human society, and human activities in the coastal region were investigated. Although there are other critical issues of land-ocean interactions in the coastal zone, they were not dealt with in this study because of limited knowledge and research experience by the author.

Nutrient-flux evaluation by the LOICZ Biogeochemical Model in Mediterranean lagoons: the case of Cabras Lagoon (Central-Western Sardinia)

In this study, the Land-Ocean Interactions in the Coastal Zone (LOICZ) budgeting procedure was used to evaluate the main nutrient pathways and ecosystem functions within Cabras Lagoon (Central-Western Sardinia, Italy) in 2004. The results of a simple one-box and one-layer model showed that nutrient accumulation prevailed over mobilisation for both dissolved inorganic phosphorus (annual mean of 675.69 mol d−1) and dissolved inorganic nitrogen (mean of 6120.05 mol d−1). Net ecosystem metabolism (NEM) was always positive, implying that production predominated over respiration throughout the year (mean of 3.3 mmol C m−2d−1). Estimates obtained from the model also highlighted the fact that nitrogen fixation prevailed over denitrification (mean of 0.14 mmol m−2d−1). Finally, extended water-residence times (mean of 192 days) were observed in the lagoon, particularly in the summer. An approach based on the improvement of water exchange with the sea would provide a relatively simple and short-term interim strategy, until more comprehensive actions aimed at reducing the anthropogenic nutrient loads in the watershed can be implemented.

Introduction: The Future of Coastal Areas – Challenges for Planning Practice and Research

Pressures on coasts and seas affect coastal and marine ecosystems as well as social and economic systems through changing patterns of resource use. Inter- and transdisciplinary research approaches are becoming increasingly prominent in assessing these changes. At the conceptual level, integrated concepts are expected to address the interactions between society and coastal ecosystems. The global research programme Land-Ocean Interactions in the Coastal Zone (LOICZ) and the German research project Coastal Futures are examples of this. At the implementation level, the concept of Integrated Coastal Zone Management (ICZM) has evolved as an alternative to traditional ad-hoc and sector-based approaches to planning and management. The article provides a brief overview of these developments and serves as an introduction to a series of articles in GAIA where selected issues of coastal change and coastal governance are addressed.

Organic Matter and Nutrient Cycling in a Coastal Plain Estuary: Carbon, Nitrogen, and Phosphorus Distributions, Budgets, and Fluxes

Abstract Nutrient temporal and spatial distributions were evaluated, in addition to budgets and fluxes derived from the Land-Ocean Interaction in the Coastal Zone (LOICZ) biogeochemical model, to determine dissolved organic matter and inorganic nutrient distribution, flux, and fate in the Mullica River–Great Bay Estuary. Seasonal cycles were observed for dissolved organic carbon (DOC), nitrogen (DON), and phosphorus (DOP) with increasing concentrations from spring to fall and maximum concentrations in summer/early fall. Annually, the estuarine system was a net source of DOC (+5 mol m−2 y−1), DON (+0.08 mol m−2 y−1), and dissolved inorganic phosphorus (DIP, +0.010 mol m−2 y−1), a net sink of dissolved inorganic nitrogen (DIN, −0.28 mol m−2 y−1), and in approximate balance of DOP (0.001 mol m−2 y−1). Overall, the upper estuary and mid-estuary served as net sinks for most nutrients, whereas the lower estuary served as a net source. Annual mean nutrient export from the lower estuary to the nearshore coastal r...

Global sea-level rise and coastal vulnerability

Global sea-level has fluctuated through geological time but the sea-level oscillations during the Quaternary and especially the last Ice Age were particularly important in shaping our modern coastline. At the last glacial maximum of 20,000 years ago, the sea level was around 120 m lower than today. It then rose rapidly to reach its current position around 6–7,000 years ago. During this period, there were times when the sea level was rising at rates in excess of 20 mm year, although the pattern, timing and rates of this major sea-level rise event vary around the world, as does the time when sea level stabilised near its present position (Harvey 2006). After a few millennia of relative stability, geological and tide-gauge data provide evidence of sea-level rise during the 19th and 20th centuries, reaching an average rate of 1.7 mm year during the 20th century (Church and White 2006). This modern sea-level rise raised concerns about the vulnerability of the significant population living near the coast, for which there are various global and sub-global estimates (Mimura 2001; Small and Nicholls 2003; Ericson et al. 2006; Woodroffe et al. 2006; McGranahan et al. 2007; Nicholls et al. 2007). Recent satellite data, combined with tide-gauge data, provide evidence of an increased sea-level rise of over 3 mm year (see Church et al.; this volume). The need to better understand the causes of sea-level rise, provide accurate predictions of the future rate of sealevel rise and to assess coastal vulnerability has been the subject of numerous scientific articles in the global change literature, which have recently been reviewed and synthesised in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (Parry et al. 2007; Solomon et al. 2007). The feature articles in this issue of Sustainability Science provide a useful contribution to this continuing debate. The idea for this issue arose from discussions following a special session on sea-level rise, held at the Open Science Conference of the ESSP (Earth Systems Science Partnership) in November 2006, Beijing, China. The ESSP comprises a partnership of the world’s four leading global change scientific research organisations: (1) DIVERSITAS (International Program for Biodiversity Science); (2) IGBP (International GeosphereBiosphere Programme); (3) IHDP (International Human Dimensions Project); and (4) WCRP (World Climate Research Program). The co-chairs of the special conference session on sealevel rise (Wilson and Harvey) brought scientists together from different global change research programs (largely the WCRP and IGBP) to present different perspectives on sea-level rise. This followed recent research efforts from the WCRP, which held a workshop in 2006 on sea-level rise and vulnerability (see Church et al.; this volume) and the IGBP and its coastal program LOICZ (Land–Ocean Interactions in the Coastal Zone), which recently published a 10-year research synthesis (Crossland et al. 2005). Four of the speakers from the ESSP conference (Church, Harvey, Nicholls and von Storch) have contributed articles to this issue of Sustainability Science with the additional help of a number of their fellow researchers. A further two papers (Syvitski and Torresan et al.) have been included to broaden the scope of the debate. The first three papers focus on physical aspects of sea-level rise, whereas the last N. Harvey (&) Geographical and Environmental Studies, University of Adelaide, Adelaide, SA 5400, Australia e-mail: nick.harvey@adelaide.edu.au

Patrick Michael Holligan: a short biography

Our understanding of the role of marine phytoplankton in the global biogeochemical cycles of carbon and sulphur, particularly the rates and variability of primary production and calcification, phytoplankton activity and ecology in the subsurface chlorophyll maximum, and the use of satellite remote sensing to detect coccolithophore blooms, has progressed substantially through research initiated, led and undertaken by Patrick M. Holligan. The enthusiasm and commitment of Patrick’s colleagues for both this special issue and the symposium on “Marine Plankton: From Cells to Ecosystems” held in his honour in April 2008 at Plymouth, UK are testament to the high esteem in which he is held within the international scientific community. His expertise as a scientific leader, teacher and writer has inspired students and collaborators over more than three decades. In particular, his chairmanship during the early 1990s of the Planning Committee for the “Land-Ocean Interactions in the Coastal Zone” (LOICZ) project led to the establishment of a new core project within the International Geosphere-Biosphere Programme (IGBP). As the first Head of the School of Ocean and Earth Science (SOES), University of Southampton (1998– 2002), Patrick had responsibility for substantial expansion of the School, including 13 new academic appointments. As one of the first UK Principal Investigators to propose an open-ocean latitudinal time-series study, he helped initiate the development of the Atlantic Meridional Transect (AMT) programme (www.amt-uk. org), and as the President of the Council of the Sir Alister Hardy Foundation for Ocean Science (SAHFOS), he guided the transition to a new Directorship of the Continuous Plankton Recorder programme. Patrick gained an MA in Botany from Christs College, Cambridge in 1966. He then moved to the Department of Botany at the University of Leeds where he completed his PhD in 1970 on “Carbohydrate metabolism in the fungus Dendryphiella salina“ under the supervision of David Jennings. During the first year of his PhD, Patrick assisted Ed Drew in some research on acclimations by seaweeds to changes in light intensity and quality that required summer fieldwork in Malta. It was here that Patrick practised his self-taught skills in scuba diving, met John Woods for the first time, acted as a guinea pig for behavioural research into the effects of nitrogen narcosis, and developed a serious interest in the marine environment. While doing his PhD, Patrick also met and married his wife, Sue. Patrick then undertook a postdoctoral appointment (1969–1973) with David Lewis in the Department of Botany at the University of Sheffield to work on the physiology of higher plants infected by rust fungi. In 1973, Patrick joined the staff at the Marine Biological Association (MBA) in Plymouth UK as a Research Scientist, despite his only “marine” credentials being research on a marine fungus and his hobby of scuba diving. He sought external advice from David Cushing and Tim Wyatt at Lowestoft and from Jack Talling at Windermere about developing a new research programme on marine phytoplankton and then, over morning coffee, met Robin Pingree, a physicist with an interest in biology who had come from the Institute of Oceanographic Sciences (IOS), Wormley, UK to work