Chlorophyll enhancement in the central region of the Bay of Biscay as a result of internal tidal wave interaction

A multi-sensor satellite approach based on ocean colour, sunglint and Synthetic Aperture Radar imagery is used to study the impact of interacting internal tidal (IT) waves on near-surface chlorophyll-a distribution, in the central Bay of Biscay. Satellite imagery was initially used to characterize the internal solitary wave (ISW) field in the study area, where the “local generation mechanism” was found to be associated with two distinct regions of enhanced barotropic tidal forcing. IT beams formed at the French shelf-break, and generated from critical bathymetry in the vicinities of one of these regions, were found to be consistent with “locally generated” ISWs. Representative case studies illustrate the existence of two different axes of IT propagation originating from the French shelf-break, which intersect close to 46°N, − 7°E, where strong IT interaction has been previously identified. Evidence of constructive interference between large IT waves is then presented and shown to be consistent with enhanced levels of chlorophyll-a concentration detected by means of ocean colour satellite sensors. Finally, the results obtained from satellite climatological mean chlorophyll-a concentration from late summer (i.e. September, when ITs and ISWs can meet ideal propagation conditions) suggest that elevated IT activity plays a significant role in phytoplankton vertical distribution, and therefore influences the late summer ecology in the central Bay of Biscay.

Valuing the health benefits of physical activities in the marine environment and their importance for marine spatial planning

The marine environment provides a number of services which contribute to human well-being including the provision of food, regulation of climate and the provision of settings for cultural gains. To ensure these services continue to be provided, effective management is required and is being strategically implemented through the development of marine spatial plans. These plans require an understanding of the costs and benefits associated with alternative marine uses and how they contribute to human well-being. One benefit which is often difficult to quantify is the health benefit of engaging with the marine environment. To address this, the research develops an approach which can estimate the contribution aquatic physical activities makes to quality adjusted life years (QALYs) in monetary and non-monetary terms. Using data from the Health Survey for England, the research estimates that physical activities undertaken in aquatic environments at a national level provides a total gain of 24,853 QALYs. A conservative estimate of the monetary value of a QALY gain of this magnitude is £176 million. This approach provides estimates of health benefits which can be used in more comprehensive impact assessments, such as cost-benefit analysis, to compare alternative marine spatial plans. The paper concludes by discussing future steps.

Valuing the health benefits of physical activities in the marine environment and their importance for marine spatial planning

The marine environment provides a number of services which contribute to human well-being including the provision of food, regulation of climate and the provision of settings for cultural gains. To ensure these services continue to be provided, effective management is required and is being strategically implemented through the development of marine spatial plans. These plans require an understanding of the costs and benefits associated with alternative marine uses and how they contribute to human well-being. One benefit which is often difficult to quantify is the health benefit of engaging with the marine environment. To address this, the research develops an approach which can estimate the contribution aquatic physical activities makes to quality adjusted life years (QALYs) in monetary and non-monetary terms. Using data from the Health Survey for England, the research estimates that physical activities undertaken in aquatic environments at a national level provides a total gain of 24,853 QALYs. A conservative estimate of the monetary value of a QALY gain of this magnitude is £176 million. This approach provides estimates of health benefits which can be used in more comprehensive impact assessments, such as cost-benefit analysis, to compare alternative marine spatial plans. The paper concludes by discussing future steps.