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Oil spill forecast modelling is typically used immediately after a spill to predict oil dispersal and promote mobilisation of more effective response operations. The aim of this work was to map oil dispersal after the grounding of the MVRenaon Astrolabe Reef and to verify the results against observations. Model predictions were broadly consistent with observed distribution of oil contamination. However, some hot spots of oil accumulation, likely due to surf-zone and rip current circulation, were not well represented. Additionally, the model was run with 81 differing wind conditions to show that the events occurring during the grounding represented the typical likely behaviour of an oil spill on Astrolabe Reef. Oil dispersal was highly dependent on prevailing wind patterns; more accurate prediction would require better observations of local wind patterns. However, comparison of predictions with observations indicated that the GNOME model was an effective low-cost approach. [ABSTRACT FROM AUTHOR]

A combination of idealised modelling and satellite imagery has been used to assess the dispersal of estuarine plume water and suspended material throughout the ecologically significant marine area off the west coast of the central North Island, New Zealand. The idealised modelling was used to elucidate the relative importance of oceanographic and meteorological conditions in controlling the horizontal structure of the estuary plumes, and then compared to plumes visible in satellite imagery and environmental monitoring data. Under low to average river flows the plumes can be categorised as either non-rotational or rotational. Rotational plumes are directed southwards under light (<5 m/s SW or <10 m/s E) winds and northwards under stronger (>5 m/s SW) winds. Non-rotational plumes remain close to the estuary mouth. The type, orientation and extent of the plumes have implications for estuarine flushing and for the dispersal of land-derived contaminants into the marine environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Coastal lakes, also known as temporarily open/closed estuaries or intermittently closed and open lakes and lagoons, are common worldwide, are typically sites of high biodiversity and often contain abundant macrophyte populations. Anthropogenic stressors such as increased nutrient and sediment loading have adverse effects on submerged macrophytes, and when closed, the lack of tidal flushing makes coastal lakes highly susceptible to eutrophication. Lake openings to the sea may occur naturally, but many coastal lakes are also opened artificially, often to reduce inundation of surrounding land. Here we used a coupled hydrodynamic-ecological model (DYRESM-CAEDYM), modified to include dynamic feedback between submerged macrophyte biomass and sediment resuspension, to explore the interactive effects of multiple disturbances (openings, eutrophication and climate change) on the dynamics of primary producers in a coastal lake (Waituna Lagoon) in South Island, New Zealand. Our results indicate that with exposure to high external nutrient loads, the frequent disturbances caused by artificial openings prevent sustained dominance by algae (algal biomass averaged 192 g C m -2 with artificial openings compared to 453 g C m -2 with no openings). However, under current nutrient loading, climate change is likely to enhance the effects of eutrophication on the system (algal biomass averaged 227 g C m -2 with climate change compared with 192 g C m -2 for current climate). The model provides a decision-support tool to guide lake management in setting limits for nutrient loads and managing the opening regime, in order to prevent eutrophication and the potential collapse of the macrophyte community., (Copyright © 2017 Elsevier Ltd. All rights reserved.)