Sedimentuen toxikotasunaren azterketa integrala ekologikoki adierazgarriak diren espezieak erabiliz

Abstract

Euskal kostaldean eta, nagusiki, estuarioetan, sedimentu ugari aurkitzen ditugu, egungo zein iraganeko giza jardueren eraginez substantzia toxiko ugari metatzen dituztenak. Horrek ingurumen-arazoak dakartza, eta sedimentu horiek modu egokian kudeatzera bultzatu behar gaitu. Horretarako, kutsatzaileok sedimentuetan duten portaera ulertu behar da, bai eta sedimentuen karakterizazio sakona egin ere. Gaur egunean indarrean dagoen legediak zenbait gidalerro eskaintzen dituen arren, hainbat lanek gidalerro horien mugak agerian utzi dituzte. Bereziki garrantzitsua da ohiko neurketa kimikoak sedimentuetan bizi diren organismoen ikerketekin uztartzea. Izan ere, haietan burutzen diren entseguek informazio oso baliagarria eskain dezakete sedimentuen toxikotasunaren eta, beraz, haien kudeaketa-beharraren inguruan. Entsegu horietarako erabiltzen diren bizidunek sedimentuan bizitzea eta han funtzio ekologiko garrantzitsua izatea komeni da. Horien artean Hediste diversicolor poliketoa dugu, sedimentuen kutsaduraren ebaluaziorako eta bioentsegu zehatz eta fidagarriak burutzeko morganismo aproposa dena. Horiez gain, in vitro teknika egokiak eta sentikorrak garatu dira espezie honetan, eta horrela esperimentazioan erabiltzen diren bizidunen kopurua mugatu egiten da. Beraz, gure sedimentuetan metatutako kutsatzaileen maila altuek izan ditzaketen arriskuen ebaluazio fidagarria lor daiteke, baldin eta analisi kimikoak eta ekologikoki adierazgarriak diren espezieetan gertatutako efektuak (analisi ekotoxikologikoak) integratzen badira.; In the Basque coast and mainly in estuaries, sediment deposition and accumulation occurs. It is noteworthy that different human activities have influenced on sediments that have undergone important inputs of different toxic substances over the years and even today. Since polluted sediments could pose a risk for the environment, we should proceed properly for an accurate environmental management. For that, firstly it is necessary to study and understand the behavior of pollutants in sediments and then to carry out characterization of sediments. Although the legislation currently in force provides certain guidelines, several works have revealed the limitations of these policies. Therefore, in addition to conventional chemical measurements, organisms living in estuarine sediments and tests performed in them can provide very useful information on sediment toxicity (and thus future use and management). Mainly, if these sentinel organisms are ecologically relevant species that inhabit those niches. Among organisms living in sediment, the polychaete Hediste diversicolor has been used for sediment toxicity assessment using bioassays. Moreover, in vitro techniques have been described in this species as very useful tools, limiting the number of organisms used in experiments and showing them as sensitive tools. Therefore, a reliable assessment of the hazards resulting from high levels of pollutants in sediments can be achieved, after integrating chemical analysis and effects measured in ecologically relevant species (ecotoxicological analysis).