environmental-dna-sampling-from-whale-watching-vessels-for-cetacean

Environmental DNA Sampling from Whale-Watching Vessels for Cetacean Monitoring

Environmental DNA (eDNA) offers a non-invasive approach for monitoring cetaceans, yet its widespread application from operational platforms requires ...

Politecnico di Milano DICA Civil and Environmental Engineering Department

Ocean liming (OL) is a potential carbon dioxide removal (CDR) method that aims to increase the ocean's capacity to absorb atmospheric CO by adding hydrated lime to the surface ocean. Modeling studies indicate that OL may cause temporary pH spikes lasting several minutes, depending on the lime sparging rate. Little is known about the short-term effects of these spikes on marine organisms. Aim of the present study is to investigate these effects on the copepod Acartia tonsa. Copepods were exposed to different pH conditions (9, 10, 11, 12) by dosing different hydrated lime solutions. Copepod mortality, movements, and behavior were recorded. At pH 9 for short exposure times (<6 h), no negative effects were observed indicating a potential tolerable threshold for OL applications. At longer exposure times (>6 h) and pH higher than 9, negative effects (mortality and sublethal effects) were found significantly higher than in the control.

Short-term impact assessment of ocean liming: A copepod exposure test.

Governments are increasingly monitoring meso- and microplastic (M/MP) pollution in surface waters to develop cost-effective solutions. While citizen science is widely used in programs like the EU's Marine Litter Watch and NOAA's sampling in the U.S., these efforts primarily focus on macro litter, leaving gaps in M/MP data, especially in under-sampled regions like Icelandic waters. This study addresses this gap through a citizen science initiative (2019-2023) that monitored M/MP pollution in the "Northeast Iceland Hope Spot." Fifty-eight trawl samples were collected from whale-watching and expedition vessels using a low-tech aquatic debris instrument (LADI) or a high-speed AVANI trawl. M/MP were present in 86 % of samples, with an average density of 0.02 ± 0.03 particles/m. Concentrations varied significantly between sites (p = 0.005), peaking in Grímsey (0.070 ± 0.03 particles/m), followed by Eyjafjörður (0.006 ± 0.04 particles/m) and Skjálfandi Bay (0.004 ± 0.03 particles/m). Mesoplastics comprised 44 % and microplastics 56 %, primarily polyethylene (47 %) and polypropylene (39 %)-common materials in fishing gear and household plastics. These findings suggest that local currents and fishing activities influence M/MP distribution. Comparison with previous studies validates the use of the presented citizen science methods for tracking floating M/MP in coastal waters and highlights their value in shaping marine conservation policies, particularly in vulnerable subarctic ecosystems.

Validating citizen science for community-driven microplastic monitoring and marine protection in Northeast Iceland's Hope Spot.

Mitigating global warming requires urgent reductions in carbon dioxide (CO₂) emissions and the development of Carbon Dioxide Removal (CDR) strategies. pH-equilibrated Ocean Alkalinization (pHOA) has emerged as a promising method to enhance CO₂ sequestration while minimizing potential environmental risks. This study investigates the ecological impact of pHOA on phytoplankton communities through a mesocosm experiment in the Gulf of La Spezia (Italy) using local seawater treated with Limenet® technology. We assessed planktonic responses to different levels of bicarbonate-enriched seawater (Control, Low, Medium, High, Oversaturated) by monitoring changes in carbonate chemistry, nutrient availability, and phytoplankton community composition over 15 days. Results revealed that pHOA treatments (excluding the oversaturated condition) helped maintain greater ecological stability, reducing the rate of diatom/dinoflagellate community shifts and supporting higher silicon uptake, particularly by diatoms. In contrast, oversaturation led to carbonate precipitation and a significant loss of added alkalinity. The findings suggest that moderate pHOA may enhance phytoplankton resilience and promote diatom activity under altered carbonate chemistry. This study underscores the need for further research to evaluate the broader ecological implications of pHOA.

The response of phytoplankton to pH-equilibrated ocean alkalinization: A mesocosm experiment with harbour waters.

Marine biodiversity faces challenges due to climate change, pollution, and human activities. Conservation efforts are often constrained by limited resources and public disengagement. This study evaluates the potential benefits of incorporating environmental DNA (eDNA) sampling and citizen science into whale-watching tours to raise environmental awareness and promote marine conservation. A Likert-scale questionnaire evaluating attitudes, knowledge, and willingness to contribute to conservation through financial support, behavioral changes, and volunteering was administered to 224 participants across the Pelagos Sanctuary (Italy), the Azores (Portugal), and Skjálfandi Bay (Iceland). Environmental awareness, interest in environmental DNA (eDNA), and higher education levels were identified as significant predictors of willingness to pay (WTP). Conversely, higher ticket prices negatively impacted financial commitment. The majority of respondents reported an increased awareness of marine biodiversity and eDNA, along with a strong sense of personal responsibility toward marine protection. The study outlined various participant profiles, indicating how age, education, and ecotourism experience influence conservation attitudes. Specifically, younger individuals who are highly educated and have prior whale-watching experience were more inclined to provide financial support and engage in citizen science activities. These findings demonstrate that integrating citizen science-based activities and environmental DNA (eDNA) sampling, into whale-watching tours is an effective way to foster meaningful pro-environmental engagement. This model presents a scalable and cost-effective approach to enhancing public participation in marine conservation and biodiversity monitoring, with potential applications extending to broader marine governance and ecotourism settings.

Article	Year
Short-term impact assessment of ocean liming: A copepod exposure test. Marine pollution bulletin\| PubMed ID: 38043201	2024
Validating citizen science for community-driven microplastic monitoring and marine protection in Northeast Iceland's Hope Spot. Marine pollution bulletin\| PubMed ID: 39938198	2025
The response of phytoplankton to pH-equilibrated ocean alkalinization: A mesocosm experiment with harbour waters. Marine pollution bulletin\| PubMed ID: 41066847	2026
Willingness to engage in marine conservation through eDNA-informed citizen science on whale-watching platforms. Scientific reports\| PubMed ID: 41290929	2025

Eleonora Barbaccia

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