Biomarkers

The occurrence of imposex and intersex in different marine prosobranch gastropods are used as biological marker for effects of the contamination of hazardous substances within NOVA 2003.

Imposex and intersex are two different morphological ways, where endocrine disruption is visibly expressed in gonochoristic marine snails. The females develop irreversible masculine sexual characters, which in the most advanced stages can result in sterility. These malformations are developed as a specific response on tributyltin (TBT), which is used as antifouling agent on many larger vessels.

The severity of imposex in marine snails sampled within a local area can be described with different parameters. Respectively with a frequency of females with imposex (%), a Vas Deference Sequence Index (VDSI), a Mensink Sequence Index (MSI) also called Penis Classification Index (PCI) and/or a Relative Penis Length Index (RPLI).

Following species of neogastropods are routinely examined for imposex: The netted whelk (Hinia reticulata), the common whelk (Buccinum undatum) and the red whelk (Neptunea antiqua).

In the same way can the intensity of intersex be described with a frequency (%), a InterSex Index (ISI) and/or a average Prostata Length in females (aFPrL). The mesogastropod periwhinkle (Littornia littorea) is examined for the development of intersex.

In addition, males of L. littorea are examined for the number of penis glands, which is addressed with an average value of penis glands (PGI).

It shall be noticed that the different species of marine gastropods have different sensitivity of TBT as they are more or less likely to develop imposex/intersex. The imposex/intersex values for the different species can therefore not be directly compared.

Data

Information on sampling locations within the Danish national marine monitoring program (NOVA 2003) and download of data can be accessed.

Inquires concerning data or comments on the page can be sent to Jakob Strand.