Current modeling practices for social-ecological systems (SES) are often qualitative and use causal loop diagrams (CLDs), as these models promote an evaluation of the systems loops and variable connectivity. Our literature review demonstrated that quality assurance of these models often lacks a consistent validation procedure. Therefore, a guide to improving the validation of qualitative models is presented. The presumed utility protocol is a multi-dimensional protocol with 26 criteria, organized into four dimensions, designed to assess specific parts of the modeling process and provide recommendations for improvement. This protocol was applied to three demonstration cases, located in the Arctic Northeast Atlantic Ocean, Macaronesia, and the Tuscan archipelago. The “Specific Model Tests” dimension, which focuses on the structure of the model, revealed positive evaluations of its structure, boundaries, and capacity to be scaled up. "Guidelines and Processes", which focuses on the meaning and representativeness of the process, showed positive results regarding purpose, usefulness, presentation, and meaningfulness. "Policy Insights and Spillovers", a dimension focused on the policy recommendations, revealed a high number of "not apply", indicating that several criteria are too advanced for the status of the models tested. The "Administrative, Review, and Overview" dimension, which focused on the managerial overview, showed the models needed improvement in the documentation and replicability, while time and cost constraints were positively evaluated. The presumed utility protocol has shown to be a useful tool providing quantitative and qualitative evaluations for an intermediate evaluation of the model-building process, helping to substantiate confidence, with recommendations for improvements and applications elsewhere.
Automated fish documentation processes are in the near future expected to play an essential role in sustainable fisheries management and for addressing challenges of overfishing. In this paper, we present a novel and publicly available dataset named AutoFish designed for fine-grained fish analysis. The dataset comprises 1,500 images of 454 specimens of visually similar fish placed in various constellations on a white conveyor belt and annotated with instance segmentation masks, IDs, and length measurements. The data was collected in a controlled environment using an RGB camera. The annotation procedure involved manual point annotations, initial segmentation masks proposed by the Segment Anything Model (SAM), and subsequent manual correction of the masks. We establish baseline instance segmentation results using two variations of the Mask2Former architecture, with the best performing model reaching an mAP of 89.15%. Additionally, we present two baseline length estimation methods, the best performing being a custom MobileNetV2-based regression model reaching an MAE of 0.62cm in images with no occlusion and 1.38cm in images with occlusion. Link to project page: https://vap.aau.dk/autofish/.
This article explores how adopting a combined ecosystem and justice approach to deep-sea mining (DSM)-particularly in vulnerable regions like the Arctic-would constitute a paradigm shift in ocean environmental law and governance. Such a shift would move ocean governance beyond fragmented, technocratic, and resource-driven frameworks toward an integrated, equitable, and sustainability-centered regime grounded in ecological integrity, social justice, and respect for human rights and local traditions.
Continuous inspection and mapping of the seabed allows for monitoring the impact of anthropogenic activities on benthic ecosystems. Compared to traditional manual assessment methods which are impractical at scale, computer vision holds great potential for widespread and long-term monitoring.
We deploy an underwater remotely operated vehicle (ROV) in Jammer Bay, a heavily fished area in the Greater North Sea, and capture videos of the seabed for habitat classification. The collected JAMBO dataset is inherently ambiguous: water in the bay is typically turbid which degrades visibility and makes habitats more difficult to identify. To capture the uncertainties involved in manual visual inspection, we employ multiple annotators to classify the same set of images and analyze time spent per annotation, the extent to which annotators agree, and more.
We then evaluate the potential of vision foundation models (DINO, OpenCLIP, BioCLIP) for automating image-based benthic habitat classification. We find that despite ambiguity in the dataset, a well chosen pre-trained feature extractor with linear probing can match the performance of manual annotators when evaluated in known locations. However, generalization across time and place is an important challenge.
An analytical framework is presented to describe the attenuation of regular and irregular waves propagating over floating seaweed farms. Kelp blades suspended on longlines are modelled, as a first approximation, as rigid bars rotating around their upper ends. Assuming small-amplitude blade motions under low to moderate sea conditions, the frequency-dependent transfer function of the rotations can be obtained, with quadratic drag loads linearized. Subsequently, the hydrodynamic problem with regular waves propagating over suspended seaweed canopies is formulated using the continuity equation and linearized momentum equations with additional source terms in the vegetation region. Analytical solutions are obtained for attenuated regular waves with their heights decaying exponentially as they propagate over the canopy. These solutions are utilized as the basis for predicting wave attenuation of irregular waves while stochastic linearization of the quadratic drag loads is employed. In contrast to energy-conservation-based models, which assume the velocity profile follows linear wave theory, the present solution can predict the reduced velocity inside the canopy. The analytical solutions are validated against experimental data and verified against a numerical flow solver. The model is capable of resolving the wave attenuation, along with velocity profiles and phase lag. Drag and inertial force exhibit cancellation effects on wave decay and both affect phase lag.
We contribute to the identification of marine biodiversity status and changes in the coastal area of Southeast Greenland through consultation with holders of local and Indigenous knowledge (LEK/IK). Through in-depth interviews with coastal fishermen and hunters in the Ammassalik area, we explore a range of changes to known and new species in relation to ecosystem dynamics. Key observations include diminishing presence of polar cod (Boreogadus saida), new abundance of known fish species (Gadus morhua, Salvelinus alpinus, Reinhardtius hippoglossoides, Cyclopterus lumpus), inflow of new/rare species of whales, fish, and shellfish (Oncorhynchus gorbuscha, Lamna nasus, Paralithodes camtschaticus, Physeter macrocephalus, Globicephala melas, Megaptera novaeangliae, Phocoena phocoena), and increasing absence in the fjords of some local seal species (Cystophora cristata and Pusa hispida). Observed changes in local abundances are understood with reference to the physical changes in temperature, ocean currents, glacier melt, and snowfall. Changed dynamics in prey-predator relationships are observed to mediate the local presence of target species. Other environmental changes include an influx of new food items in food chains and increased seaweed growth. Our study confirms the relevance and timeliness of systematically incorporating local and Indigenous knowledge to enhance the understanding of coastal marine dynamics in the context of climate change and the geographical 'opening' of the East Greenlandic region.
Crude oil and cadmium (Cd) are common pollutants in Ghana's coastal ecosystems, where the cyanobacterial phytoplankton Synechococcus sp. serves as the primary producer and forms the base of the marine food web alongside small grazers. We hypothesized that cadmium and crude oil would disrupt microbial community structure and function, with the strongest effects under combined exposure. This study investigates the toxic effects of Oil (2 mL L−1), Cd (4.4 μg L−1), and their combined impact (Cd + Oil) on functional groups within the coastal microbial community, including Synechococcus sp., heterotrophic bacteria, nanoflagellates, eukaryotic phytoplankton, ciliates, and dinoflagellates, as well as on copepod nauplii and copepodite development during six-day incubations. We observed acute toxic effects on heterotrophic ciliates and dinoflagellates, with >50 % reductions in abundance within 6 h and a marked decrease in diversity. Phytoplankton showed growth within the first 24 h due to nutrient replenishment from the protist decay, however, their growth continued to decline after 24 h, with Synechococcus being particularly sensitive to Cd and less affected by Oil. In contrast, heterotrophic bacteria increased in abundance across all treatments, likely benefiting from organic matter released during phytoplankton decay and their high adaptability. Notably, the bacterial genera Marivivens and Rhodovulum became dominant mainly in the Oil-amended treatments. Overall, the microbial groups exhibited diverse responses to the pollutants, with the combined Cd + Oil treatment exerting the strongest negative effects, while crude oil alone had the least impact. These findings highlight the vulnerability of tropical microbial food webs, typically dominated by Synechococcus and microbial grazers, to combined pollutant stress, with potential cascading effects on higher trophic levels and coastal ecosystem productivity. This highlights the need for comprehensive monitoring and conservation efforts in these globally significant, yet understudied, regions.
Commercial small-scale fisheries along the Baltic Sea coasts have declined over the years although these fisheries are viewed as important for coastal development and food security at the local, national, and EU levels. The viability and future of small-scale fisheries are severely challenged by problems caused by grey seals. The conflict, occurring between Baltic Sea coastal fisheries and conservation of the grey seals, has been severe since the mid-1990s and continues despite attempts to find a more balanced situation. Resting on reviews of multiple material, this paper explores the state-of-the-art opportunities for mitigating the seal-fisheries conflict and asks how these are related to social struggles and social justice. Our paper concludes that co-existence of coastal fisheries and the grey seal is possible but necessitates political will and co-designed seal management plans that help implement context-specific measures. Seal deterrents, for instance, give hope as a supplementary conflict mitigation measure – along with seal-proof fishing gear – but provide only partial relief. From the fisheries sector’s position, influencing the size of the seal population is a logical solution. The lifting of the EU trade ban of seal products as a regional derogation would allow sustainable management of seal populations so that they be used as renewable natural resource. Monitoring changes in the seal population is crucial for maintaining a balanced population. Reaching co-existence is timely, because – unlike the seal – the diverse Baltic coastal fishing culture is increasingly endangered.
Life depends on healthy oceans that provide ecosystem services (ES) to humans, including provisioning, regulating, supporting, and cultural ES (Kovalenko et al., 2023). However, biodiversity, habitats, and the delivery of marine ES and resources are increasingly threatened by growing human activities in the oceans (Worm et al., 2006). Blue-growth activities, such as shipping and energy, eutrophication, and climate change represent major pressures that affect marine ecosystems (Halpern et al., 2008; Ehlers, 2016). Over the past two decades, increasing scientific attention has focused on the need to preserve and restore healthy marine waters and their role in adapting to climate change (Santos et al., 2020). This challenge calls for holistic approaches that advance our knowledge. Within the contributions to this Research Topic (see Figure 1), three themes are central to driving further research to expand our understanding in this interdisciplinary field.
Fishing and sand mining in Cambodia may not appear to have much in common. However, digging deeper reveals important parallels. Both fishing and sand mining support livelihoods and are connected to a limited natural resource. Meanwhile, they are both typified by precarious livelihoods, on the one hand, and overexploitation, on the other. In bringing these two topics together, the paper combines empirical qualitative research from two separate studies conducted by the co-authors in Cambodia, one in coastal fishing villages and another in the sand mining industry along the Mekong River. We argue that the interplay between fishing and sand mining has paradoxical impacts on livelihoods, supporting one group while undermining another. Using a precarity analysis lens, we show how an unconventional, and largely invisible frontier of natural resource exploitation—sand mining—is intertwined with fisheries, and expands our understanding of the relationship between precarious labour, environmental change, and livelihoods.