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- Automatic acoustic target detection and classification off the Coast of PortugalPublication . Sabara, Razi; Soares, Cristiano; Zabel, Friedrich; Valente de Oliveira, José; Jesus, SergioOcean noise has been a topic of research for many years, for its impact in sonar detection, underwater communications and ocean acoustic observation in general. Recently, ocean sound has been designated as an Essential Ocean Variable (EOV) and is therefore, becoming increasingly recorded and monitored, along with other oceanic and meteorological variables. The research projects EMSO-PT and SUBECO aim at deploying ocean observatories along the coast of Portugal for long term ocean variables monitoring, among which ocean sound. Unlike other ocean variables, ocean sound allows for feature detection, characterisation and possibly identification with known patterns. This work shows the results obtained with current machine learning algorithms for feature detection and extraction on a two days recording of ocean noise obtained on a offshore buoy deployed under the SUBECO project, on the west coast of Portugal. Preliminary results show the possibility of improved event detection, followed by classification and clustering, that foresee a rapid and accurate analysis of large observatory acquired acoustic data sets.
- Shipping noise predictions from AIS in the Faial-Pico area, Azores archipelagoPublication . Soares, Cristiano; Duarte, Ricardo; Zabel, Friedrich; Silva, Monica A.; Jesus, SergioThe Azores archipelago, lying on the North Atlantic (NA) ocean, hosts one of the greatest diversities of cetaceans, and is an important habitat for several resident and migratory species. However, this unique diversity may be at risk due to the ocean noise generated by increasing commercial and recreational vessel traffic in the area. AIS shipping distribution and water column variability, together with suitable numerical propagation models were used to generate noise level maps for the area around Faial-Pico-Sao Jorge Islands, during June 2018. The generated noise level time-space distribution generally agrees with detected environmental variability and known navigation in the area, namely ferries between islands and fishing patterns.
- INOVPESCA - Redução de capturas acidentais de espécies marinhas protegidas em pescarias costeiras algarvias: inovação de procedimentos e técnicas de mitigaçãoPublication . Marçalo, Ana; Carvalho, Flávia; Frade, Magda; Pires, Alexandra; Alexandre, Sofia; Bentes, Luis; Soares, Cristiano; Zabel, Friedrich; Rangel, Mafalda; Oliveira, Frederico; Monteiro, Pedro; Ressurreição, Adriana; Erzini, Karim; M. S. Gonçalves, JorgeO presente relatório é uma iniciativa do Projecto iNOVPESCA, com o objetivo de documentar o trabalho desenvolvido ao longo do projeto (2018-2021) e incentivar a implementação voluntária de medidas que contribuam para uma melhoria da relação entre as pescas e as espécies marinhas protegidas, especialmente de cetáceos, contribuindo para a sustentabilidade ambiental com a redução de capturas acidentais e sustentabilidade económica do sector das pescarias costeiras Algarvias, podendo servir de exemplo a nível nacional. Este trabalho pretende ser um documento de referência sobre o nível de interação que existe entre pescarias costeiras ao longo da costa algarvia com espécies marinhas protegidas (cetáceos, aves marinhas e tartarugas), e por outro lado, pode servir como aconselhamento para todas as entidades que beneficiam das pescas e que necessitam desta atividade para o seu desenvolvimento económico e social. Para isso foi desenvolvida uma linha de orientação sobre boas práticas assente em dois aspetos chave: - Contribuir para a consciencialização, informação e treino de todas as partes interessadas, no que se refere a medidas de mitigação de conflitos entre pescas e espécies marinhas protegidas; - Promover o uso de práticas responsáveis de pesca e otimizar, em cooperação com o sector pesqueiro, soluções que ajudem a diminuir a mortalidade acidental de cetáceos ou outras espécies protegidas (ex. aves marinhas e tartarugas marinhas) e evitar situações que contribuam para perdas económicas para o pescador (como por exemplo, danos nas artes e perda ou danos no pescado por predação). As interações entre espécies marinhas protegidas e as pescas são um problema mundial com duas componentes importantes, a da conservação, quando os animais como captura não intencional ficam presos nas artes de pesca acabando por morrer, e a socioeconómica quando os animais causam danos nas artes de pesca e na captura alvo dos pescadores.
- Comparing noise vessel azimuth tracking with a planar hydrophone array and a single vector sensorPublication . SOARES, CRISTIANO; Zabel, Friedrich; Jorge Maia dos Santos, Paulo; Silva, AntónioVector sensors are appealing for monitoring underwater noise due to its inherent directivity. While acoustic pressure sensors are ambiguous in all directions, vector sensors permit the aquisition of directional information through the measurement of particle velocity, which enables the possibility of azimuth tracking of underwater noise sources. The MARREAL marine observatory is a marine observatory equipped with a number of sensors and subsystems, including an acoustic acquisition system made of four hydrophones and a vector sensor. The observatory was deployed in September 2022 in Sagres, Portugal, near the Baleeira Port which is accessed by fisher boats and recreational boats. This paper shows preliminary results on azimuth estimation of boats passing in the deployment area, obtained independently with a 4- hydrophone planar array and a vector sensor. The results indicate that a single vector sensor can provide fair results on azimuth tracking of boats passing in the area. At high signal-to-noise ratio (SNR) the vector sensor is able to yield results similar to those obtained with the planar array. When the SNR is low the planar array outperforms the vector sensor with actual processing methods used.