After brief rainfall in the heat of summer, the stench of ammonia over seabird colonies can be overpowering. Studies have found they can emit as much as 90kg of gaseous ammonia every hour, emitted as downwind plumes after rainfall.
Then there are ocean algae, that create a huge amount of a compound called dimethyl sulphide, that combines with atmospheric oxygen to make sulphuric acid.
When the acid mixes with the birds’ ammonia, it creates atmospheric particles that seed cloud-droplets. Ammonia production is highest in the tropics where conditions tend to be warmer and wetter[2] but authors of a 2016 paper in Nature Communications [3] even found the effect to be important at Arctic seabird colonies. Their results show how cloud seed-particles can grow to diameters sufficiently large to promote “pan-Arctic cloud-droplet formation” in the summertime. In other words, in the Arctic where ammonia emissions are relatively benign, seabird colonies are creating weather systems over the whole region. Not only that, the clouds they form, reflect sunlight, maintaining the cool ground temperatures.
Similarly, marine mammals excrete bioavailableMolecules that can be metabolised by animals. Iron, for example, is extremely abundant in nature but as iron oxide (rust) which isn’t soluble in water. Iron is nonetheless vital for all animal respiration and plant photosynthesis. We rely on micro-organisms to fix the iron into forms that can be used and on animals, to concentrate it in the right time More ammonia as urea at several orders of magnitude higher concentration than surrounding seawater [4]. These and fish populations will also be part of the process.
By protecting seabird colonies, we are looking after rainfall systems that deliver water to our nations’ farmland.
1. Blackall, T., et al., Ammonia emissions from seabird colonies. Geophysical Research Letters – GEOPHYS RES LETT, 2007. 341.
2. Riddick, S., et al., Measurement of ammonia emissions from tropical seabird colonies. Atmospheric Environment, 2014. 89: p. 35–42.
3. Otero, X., et al., Seabird colonies as important global drivers in the nitrogen and phosphorus cycles. Nature Communications, 2018. 9.
4. Roman, J. and J.J. McCarthy, The Whale Pump: Marine Mammals Enhance Primary ProductivityThe power of an ecosystem to process energy. The most productive ecosystems have reached a steady stable-state with maximum entropy production. That’s to say, the number of species has reached an optimum and the functions they fulfil, have translated free surplus energy into nutrients that is either stored inside plants and animals, or is entrained within the biological cycles that More in a Coastal Basin. PLOS ONE, 2010. 5(10): p. e13255.
