Six marine-derived fungi (Alternaria sp. D11, Alternaria sp. D21, Cadophora sp. D43, Cadophora luteo-olivacea D51, Phoma sp. K2BR, Phoma sp. K21) were isolated from the Cakalburnu Lagoon, Izmir Bay, Aegean Sea in Turkey. An effective method has been developed for marine-derived fungi isolation and laccase production of the fungi has been studied. This method consisted of immersing a sterile solid substrate containing lignin into the aquatic system under aseptic conditions and removing at the end of 10 days, isolation for laccase producing fungi of marine origin. The decolorization potential of the isolate Alternaria sp. D21 with the highest laccase activity was investigated for dyes containing azo, anthraquinone, triarylmethane and heterocyclic chemical classes. The decolorization rates were determined as 98% for Methyl orange, 93% for Acid green 3, 78% for Methylene blue, 71% for Remazol Brilliant Blue, 58% for Crystal violet, and 53% for Congo red after 144 h at 100 mg/L concentration of dyes. The ability of the marine-derived fungi to remove dyes of different chemical classes is also promising for waste containing mixtures of various pollutants. (C) 2021 Elsevier B.V. All rights reserved.