For that you use an Environmentally Acceptable Lubricant, such as SKF LGGB 2. An EAL meets minimum requirements for biodegradability, toxicity, and bioaccumulation under the criteria of the US EPA’s Vessel General Permit, making the risk to aquatic life significantly lower than with a conventional grease. Biodegradable, incidentally, doesn’t mean discharge is permitted — it reduces the risk, it doesn’t replace the regulations.