Michael Ellis wades into tidepools and finds one of his favorite creatures.
As most folks know intuitively, edges are the most diverse areas in nature. In a mature redwood forest, it is often profoundly still; likewise in the nearby scrub. Yet where the forest meets the chaparral, there is an increase in life and in action. At this interface there exists a greater variety of habitats and niches---opportunities for plants and animals to exploit. Biologists have coined the word "ecotone" to describe this location.
The tidepool area along the coast of California is one of the richest ecotones in the entire world. It is an edge---the edge between the North American continent and the Pacific Ocean and the edge between solid and liquid. The cornucopia of intertidal life here is due to several factors: upwelled, nutrient-rich water which fertilizes the top layer of the sea and fuels a prodigious food web; an absence of killing frost and destructive winter ice; and summer fog which protects the sensitive plants and animals from desiccation.
Of all the beautiful creations in these tidepools, those I hold most dear are the sea slugs. Slugs! What an ignoble name for such delightful creatures. I prefer the "butterflies of the sea." They come in a diverse array of forms and colors - iridescent blue, shocking pink, orange with purple spots, or even transparent. Some are tufted with large plumes; others are warty and smooth. Because they are small and not good for human consumption they are often overlooked.
June is a good month for tidepooling. There are usually no storms. The tides are extremely low and often occur in the morning before the wind begins to blow and one's coffee wears off. Try to arrive at least 90 minutes before the low tide in order to follow the receding water out. Dress warmly and count on wet feet. Exercise ocean awareness at all times. Occasionally edges can be hazardous to your health.