A new approach to classifying polymer type of microplastics based on Faster-RCNN-FPN and spectroscopic imagery under ultraviolet light.

Hazardous compounds from microplastics in coastal and marine environments are adsorbed by live organisms, affecting human and marine life. It takes time, money and effort to study the distribution and type of microplastics in the environment, using appropriate expensive equipment in a laboratory. However, deep learning can assist in identifying and quantifying microplastics from an image. This paper presents a novel microplastic classification method that combines the benefits of UV light with deep learning. The Faster-RCNN model with a ResNet-50-FPN backbone was implemented to detect and identify microplastics. Microplastic images from the field taken under UV light were used to train and validate the model. This classification model achieved a high precision of 85.5-87.8%, and the mAP scores were 33.9% on an internal test set and 35.7% on an external test set. This classification approach provides a high-accuracy, low-cost, and time-effective automated identification and counting of microplastics.

Two new species of the marine isopod genus emCirolana/em Leach, 1818 (Crustacea: Isopoda: Cirolanidae) from the coast of the western Gulf of Thailand.

Cirolana khamensis sp. nov. and C. parawongat sp. nov. are described from specimens collected in the western Gulf of Thailand at depths of 8 metres and 1 metre, respectively. Both species belong to the Cirolana 'pleonastica-group' with tubercles on the dorsal surfaces, transverse sutures on the pereonites, pleonite 3 not posteriorly produced and pleonite 4 posterolaeral margin rounded. Cirolana khamensis sp. nov. can be distinguished from other species of Cirolana 'pleonastica-group' by lateral margin of uropodal exopod having five robust seatae and a continuous row of plumose marginal setae, pereonites 1-3 each with a single transverse impressed line; antennula peduncle with articles 1 and 2 distinct and articulated peduncle; pleotelson dorsal surface with two sub-median longitudinal carinae, each of which has four prominent tubercles. Cirolana parawongat sp. nov. can be distinguished by pereonites 1-3 without a single transverse impressed line and having nine tubercles on pleonite 4 and 5. A dichotomous key to Cirolana 'pleonastica-group' in South-East Asia region is given.

Cirolana phuketensis, a new species of marine isopod (Crustacea, Isopoda, Cirolanidae) from the Andaman Sea coast of Thailand.

Cirolana phuketensissp. n. was collected from coral rubble from the Andaman sea coast of Thailand. C. phuketensissp. n. is described and fully illustrated; C. phuketensissp. n. can be recognized by the presence of transverse sutures on pereonites 2-4, pereonite 7 having three transverse sutures forming a nodulose ridge, antennula peduncle with articles 1 and 2 fully fused; pleotelson dorsal surface with 2 sub-median longitudinal carinae, each of which has one prominent tubercle, lateral margins weakly convex, and posterior margin narrow and rounded; 6 molariform robust setae pereopod 1 on inferior margin of merus and the penial openings are two low tubercles. A dichotomous key to species of Cirolana in Thailand is given.

Cirolana songkhla, a new species of brackish-water cirolanid isopod (Crustacea, Isopoda, Cirolanidae) from the lower Gulf of Thailand.

Cirolana songkhla sp. n. was collected from brackish-water habitats including lagoons and estuaries in the coastal zone of the lower Gulf of Thailand. C. songkhla sp. n. is described and fully illustrated; C. songkhla sp. n. can be recognized by the presence of abundant chromatophores dorsally, lack of ornamentation on the posterior pereonites, pleonites and pleotelson, the number of robust setae on the uropodal and pleotelson margins (uropod exopod lateral margin with 12-14 RS, mesial margin with 5-8 RS; endopod lateral margin with 8-10 RS, mesial margin with 11-13 RS; pleotelson with 12-15 RS) and lack of setae on the endopods of pleopods 3-5. A dichotomous key of brackish Cirolana species in Thailand is given.