This paper explores the representation of biological and linguistic diversity in Zoe Skoulding’s latest collection A Marginal Sea (2022). I argue that in Skoulding’s hands, languages become a form of playful experimentation - in poetic form, visual format, voice and perspective - which defamiliarizes and re-figures its subject matter: the multiple species inhabiting the ‘marginal’ coastal areas of/off Ynys Môn/Anglesey. Close readings of poems including ‘Weather This’, ‘The Island’, ‘Red Squirrels in Coed Cyrnol’ and ‘Adar Môn Birds of Anglesey’ will show how Skoulding re-situates us - the animal at play with words - within a biosphere whose dynamic flux is experienced anew again and again in ‘this body’s opening’ each ‘good morning’. Through poems about encounters with the red squirrel, the cormorant, the curlew, and the oystercatcher among others, Skoulding’s speakers experience and question themselves in relation to these other species. The paper will argue that in response to the environmental crisis of our times, Skoulding’s work reaches towards a politics of cross-species community, one that recognises the ultimate otherness of the world around us: ‘Why should you give yourself up / in a code I can read’.