"There are two classes of water which make the highest appeal to the imagination and the emotion. There are those, which are unknown and unfished, whose mysterious depths may contain anything, and which you are the first to explore. But an emotion equally strong, though different, is given by fishing a river which has been fished for centuries. As I walk its banks, I like to think of those who walked before me."
Holistic Biology will focus on the ecology of rocky shores and the coastal ocean, including fisheries and other human impacts. These are the systems in which Steinbeck and Ricketts immersed themselves in the 1930's, and both played a formative role in their philosophy and writing. Hopkins Marine Station, a center of research and teaching on the shores of Monterey Bay for over 100 years, has been joined by so many other research and teaching institutions that the regional marine ecosystem has arguably become the most thoroughly studied in the world. On the other hand, the Sea of Cortez largely retains much wilderness.
But changes are taking place in both regions, and it remains a major challenge to elucidate the factors that determine how species, populations and communities are structured in space and time and to identify impacts of anthropogenic forcing on these natural systems. We will take advantage of the rich biology of Monterey Bay and Baja California to extend our understanding of complex natural systems. As a team, we will engage in research that addresses broad as well as focused questions.
1. Long-term changes in the rocky intertidal fauna at Hopkins Marine Station
During the first several weeks at Hopkins we will examine the composition and community structure of the local invertebrate fauna. We will adapt the views of Ed Ricketts described in his landmark work Between Pacific Tides to the contemporary picture. As part of this, we will become familiar with the relevant local invertebrate species and carry out transects at a site established in 1931 by Willis Hewatt and more recently re-examined by Baxter and colleagues, including then-undergraduate Rafe Sagarin, who will join us in Mexico ( Barry et al., 1995: Science. 267:672). Long-term changes in the presence and abundance of certain species were observed that were consistent with a warming of the local climate, but no quantitative work has been carried out for over a decade. As a class we will repeat this transect in order to begin a monitoring program that will continue into the future. We will pay particular attention to selected taxa that are important both in Pacific Grove and in the Sea of Cortez, including echinoderms (sea stars, urchins, brittle stars and sea cucumbers) and certain snails (predatory species and tube-dwelling, vermetids) .
We will carry out quantitative vertical transects, identifying and counting all invertebrates (limpets, snails and barnacles) on the same rocks that were first studied by Hopkins Professor Don Abbott and co-workers in 1947 and more recently by our colleagues John and Vicki Pearse in 2007 and the Holistic Biology class in 2008. John and Vicki will both be working with the class, and this effort will become part of a long-term monitoring program of this high-intertidal community. Data collected by our efforts will become part of the database associated with the Hopkins Marine Life Observatory.
2. Long-term changes in the rocky intertidal fauna in the Sea of Cortez.
In Mexico we will extend the background obtained at Hopkins to representative sites in the Sea of Cortez that were studied by Steinbeck and Ricketts in 1940, by our group in 2004 and by Holistic Biology in 2006. These include sites near downtown La Paz ( Caimancito ), on nearby islands Espirtu Santo ( Punta Lobos ), Cayo ( Cayo ). In addition, we will study two remote sites ( Punta San Francisco and Punta Marcial ) located near Rancho San Marta on a roadless section of coast north of La Paz. We will carry out quantitative transects along established courses that will allow our data (and future data) to be compared to previous sampling (Hopefully the markers are still there!). We will also utilize the time-honored “boulder-rolling ” method of sampling, which reveals a many species that are generally not encountered in the transects. We will also explore the rich mangrove ecosystem on Isla San Jose at Amortajada.
Again, the goal will be to determine how intertidal communities are changing, from 1940 to today and into the future. Based on our 2004 work, we found three major changes from 1940 that were widespread: i) a large decrease in the number of echinoderm species and individuals; ii) a decreased presence of large predatory snails and an increase in smaller snails; iii) a large increase in the abundance of tube-dwelling, vermetid snails. Work by our class will serve to follow these apparent changes into the future. In 2008 we discovered a radical take-over of the intertidal by sea lettuce at Punta Lobos, but whether this was a seasonal or long-term phenomenon remains to be determined thorough future efforts.
3. Oceanography and pelagic biology in the Sea of Cortez
We will carry out a variety of activities aimed at furthering our understanding of the behavior and life history of the jumbo squid and of local oceanographic features relevant to the species. Although the squid fishery is presently the third largest in Mexico (~100,000 tons per year), it is essentially artisanal (Fig. 3 & Fig. 4). Amazingly, jumbo squid were not recorded by Ricketts 1940.
We will work on the live-aboard vessel, Don Jose, departing from La Paz to work at sea across the Gulf off the Sonora coast. In 2008 we discovered a new ‘hot-spot’ for Humboldt squid and their main predator, sperm whales, near the small, rugged island, Farallon de San Ignacio. We will search for these creatures again in this area in 2010. As we transit across the Gulf we will deploy an instrument to depths of 600 meters that measures conductivity (salinity), temperature, depth (pressure), oxygen and fluorescence (chlorophyll) – the first three parameters give the instrument its name, CTD profiler. We will compare these physical properties of the water column to the position of layers of planktonic organisms using acoustic (sonar) methods. In addition, we will also carry out plankton tows to sample zooplankton and attempt to identify squid paralarvae. The picture we develop will be relevant to basic understanding of squid ecology and to development of a squid-fishery management plan in Mexico.
During this leg of the voyage in 2010, we will catch adult squid and study their diet through analysis of stomach content. We will also have an opportunity to deploy a National Geographic Crittercam in a collaboration with the NG Remote Imaging Department. The squid will carry this camera during daylight hours, and we hope to capture natural behaviors of free-swimming squid without any interference from human divers, bright lights or submarine vehicles. The camera package will detach from the squid before dusk, and we will retrieve it using a VHF radio beacon. These data will reveal how the squid utilize the midwater environment, particularly a hypoxic zone called the oxygen minimum zone. This environment is expanding in the Pacific, and we know relatively little about it at present. Sperm and pilot whales are primary predators on jumbo squid, and they may be locally abundant when we are working. If so, we will record vocalizations by sperm whales with a Mexican colleague. We will also see a large variety of seabirds, including several species of boobies, frigate birds, pelicans and ospreys. Other pelagic life such as turtles, sharks, mantas and billfishes may also be encountered. Life at sea is always to some extent an unpredictable adventure.
4. Exploration of Isla Santa Catalina.
This remote and protected island is an amazing place that we will explore over the course of several days on both land and in the water. On land, we will find endemic species, including a rattle-less rattle snake. In the shallow subtidal we will experience fish and invertebrate communities on relatively unperturbed reefs. We will also explore the intertidal.
5. Social, economic and ecological impacts of man.
We will also explore the effects man has had on the environment in Baja California Sur. We will visit a remote Jesuit mission, San Javier, in a high mountain valley that marks the start of man’s successful dominion over nature in Baja. We'll also visit the oldest mission in Baja, Loreto. In Santa Rosalia we will see the squid fishery of today in the shadows of abandoned copper smelters and mines that represent the economic life-blood of the early 20th century.