Sammendrag
Abstract
Microplastics particles such as micronized tire rubber are present widely in the aquatic ecosystem and possess great threat to wide range of aquatic organisms. Many aquatic creatures swallow microplastics because of their colour and composition, which make them look like their prey. This study investigates the rate of ingestion of micronized rubber by three-spined sticklebacks (Gasterosteus aculeatus) which were sampled from brackish water lagoon, Lake Engervann. Micronized rubbers were extracted from gastrointestinal tract of three-spined stickleback. The influence of biological factors like length, sex, plate morphs, lateral plates, and parasites on the different aspects of micronized rubber such as their presence and absence, total number of rubber particles and size of rubber particles was studied. Out of 100 sampled three-spined sticklebacks, rubber particles were found on 67 sticklebacks, the number of rubber particles ranges from 1 to 25 and mean size of rubber ranges from 1.07mm to 6.06mm. Generalized linear model was used while taking presence and absence of rubber and total number of particles as response variables whereas liner model was used while mean size of rubber was taken as response variable. The best fit model was observed through Akaike information criterion (AIC) by selecting the lowest value. Significance of predictor variables with response was observed by observing p-value (p-value<-0.05 was significant). Except for plate morph (p<-0.03) other variables did not show any influence in presence and absence of rubber particles. Body length (p-value<-0.00018***) and sex (p<-7.32e-05***) of three-spined stickleback were found significant with total count of rubber particles. Body length (p<-0.031*) had significance with the mean size of rubber particles. Trematode, Thersitina gasterostei and black spot disease were three ecto-parasites found in the three-spined stickleback, but they did not show any influence on ingestion of rubber particles. Out of all biological factors, body length was found to have more influence on the rubber particles. Further studies must be conducted in different water ecosystem to fully understand the fate of microplastics in food web in aquatic ecosystem and its adverse effect on marine biota.
Keywords: Biological factors, Gasterosteus aculeatus, Ingestion, Lake Engervann, Microplastics