James Moore: Our first speaker is Todd Braje and he’s an anthropological archeologist specializing in long term human environmental interactions, the archeology of maritime societies, historical ecological approaches to understanding coastal hunter gatherer fishers, and the peopling of the new world. As an associate professor of anthropology at San Diego State University, he conducts much of his field work on California’s northern channel islands and currently is involved with several research projects.
Todd Braje: Thanks to the organizers, I’m really happy to be here and thanks for Mike, in particular, for inviting me. It’s been a really exciting first day, so I’m looking forward to hearing what everybody has to say as we move on.
Today, I wanna just sort of … I work in an inner-discipline with an inner-disciplinary group of scientists and sort of my goals here today are threefold. To sort of describe some of our historical ecology work that use island land and seascapes as sort of a millennia long creations of MCLs. I’m gonna argue that we need to be careful not to divorce concepts of MCLs from natural resource management. Cultural resources can be very critical components of understanding, managing, and restoring natural resources. And indeed many natural resources are actually millennia long anthropogenic creations. And then at times, the management of MCLs can be in direct conflict with those natural resources. I’m going to give some examples of that.
I’m going to take you through three case studies that cut it down by one and just kind of show you some of the things we’re doing on the northern channel islands. And here they are, off the coast of Southern California, a chain of four off-shore islands. Dave gave you a little geographic background on these, where I conduct most of my research. And these islands are exceptionally productive in terms of their marine resources: Shellfish, fish, sea mammals … Relatively impoverished terrestrial resources with the largest land mammal being this very cute house-sized fox … The island fox, endemic island fox.
One of the advantages we have to working in this area is not only do we have exceptional archeological records, but we have an exceptional paleo-ecological records where we can tease apart the changes that we see in ecosystems that might be the result of either, or, and both natural or anthropogenic changes. So we can sort of look at some changes that are a result of humans or natural climatic changes like sea surface temperature, precipitation, or productivity … Marine productivity.
The archeological records on the channel islands are exceptionally long. The earliest site is this 13,000 year old set of human remains from Arlington Springs and there was continuous occupation by the Chumash and their ancestors from the terminal Pliocene to the historic period and then a series of historic occupations after abandonment and forceful removal of the Chumash by colonial enterprises. And through this 13,000 year sequence, these were maritime hunter-gatherers that relied on marine resources and developed this sophisticated maritime hunting and fishing technology, voting technology that was really geared towards … at least the protein diet, exploiting these exceptional marine intertidal and kelp forest resources.
What we’ve been engaged in is this sort of massive sampling campaign of small scale sampling of eroding exposures, all across the islands, extensive surveys and mapping, and extensive radio carbon dating to sort of build this trans Holocene record of human environmental interactions on the channel islands. One of the results of that has been, perhaps, arguably the largest and most significant concentration of terminal Pliocene you’ve seen in early Holocene sights of anywhere in the new world.
So this is despite the fact that that super island of Santa Rosa that formed during glacial periods … We’ve lost 75% of that paleo coastal landscape. This is 80 plus sights over 8500 years old that weren’t on the paleo coastline. So we’re missing this huge piece of it. And we know very little about this submerged landscape.
I’m gonna take you through a few case studies, the first one being ancient and modern abalone fisheries and sort of the creation of MCLs, these long-term fisheries on the island. And this may seem like a species approach, I assure you it’s not, so I’ll get there, hang with me. Abalone fishing and particularly red abalone fishing, used to be a multi-million dollar industry in California. It closed in 1997 because of overfishing and disease. And this was really spurred on by the depletion of otters upon predator of Abalone, that freed Abalone and other shellfish from predation pressure … And caused the explosion of abalone populations in California. Abalone has done pretty well since then, and in 2006 there were a number of former commercial abalone fishermen who suggested that we open a test fishery … A test commercial fishery around San Miguel island because this population was seen as recovering or recovered.
One of the things that we did was start to build this long-term record of abalone fishing on the islands and we have … Traditionally we’ve relied on sort of this modern data set. The modern catch records from 1950-1997 when it closed. Here that is, a really broad scale, a record, of where red abalone was abundant through this modern period on the northern channel islands. San Miguel being the prime fishery and then secondary fisheries on southern Rosa and southern Cruz.
If we look at the archeological record, abalone, red abalone in particular, really explode starting 8,000 years ago on the channel islands. So you have lots of red abalone fishing in what we call middle Holocene red abalone middance, and that just means there abalone of unprecedented sizes and abundances in archeological shell mans around the island. And this seems to be tied started 8,000 years ago to native depletion of sea otters … Either through direct hunting or scaring these animals out of local waters that resulting in declines of otter predation, an explosion in abalone and other economically important shellfish. And then, in turn, on the mainland the formation of midden dominated by these economically important shellfish. Right? So this creation, this trophic cascade, essentially ramps up at 8,000 years ago, and although dynamic has been in place since. Right, with this removal of otters as the prime predator of abalone and other shellfish.
We lay the archeological record of abalone fishing over that modern record … This 8,000 year record of abalone fishing and we see some consistency. Lots of fishing both in the modern period and in the de-pass on Miguel and secondary locations on southern Rosa and southern Cruz.
Now, the implication of this is if we look at sea surface temperature that Miguel seems starting 8,000 years ago to be the place where abalone, red abalones, always available and always abundant. Through times of warm water and cold water, through low productivity times, through high productivity times, and then it feeds the channel. San Miguel, the nursery for larval recruitment of abalone feeds the channel to the East during good times, during cold sea surface temperatures. So the management implications being, I’m not so sure a test commercial fishery on the nursery for abalone is the best strategy.
All right, so we’ve done a similar work on black abalone, closed again a commercial fishery developed in the historic period … Closed in 1993. But, the difference between red and black is black’s only on the wharf so despite 20 years of management and restoration, in 2009 black abalone was upgraded from a species of a concern to endangered, which means on the US Endangered Species Act, which means that’s really bad and we have this continued decay.
The strategy for Cal Fish and game as part of this abalone recovery management … Part of the strategy has been receding … So taking juvenile and larval black abalone and receding local intertidal systems with millions of these sub-adults and then hoping they take hold and then spread throughout a larger intertidal systems. The problem is then that places that have been identified as good places to do this are almost entire islands, in some cases. A hundred percent of the shorelines on many islands so the strategy, a historical ecology approach, has been, can we narrow these restorations targets? So again overlaying the modern period, overlaying the archeological record of black abalone harvesting and again we see some consistency in where black abalone have always been available … Where this fishing tradition for black abalone has been in place on Miguel and northwest Santa Rosa.
We can also overlay that with not only the modern and the ancient, but the historical. In the 19th century, the first commercial abalone fishery in California was started by immigrant Chinese fishermen who came seeking their fortunes in Gold Mountain and were sort of pushed to the margins on the coast and left records of black abalone fisheries … Of fishing scattered around the island landscapes. And so I’ve conducted surveys for these sites and again this combined information tells us where are sort of smaller scale places where we have these traditions of abalone fishing through deep time.
All right, so case study two is people, seals, and sea lions. We start with the 18th 19th commercial hunting in a sea of slaughter where you have this global carnage of sea mammals and whales, bringing many of these animals to the brink of extinction. So just to give you an example … A small example, in 1892, Smithsonian biologists identified what they thought to be the last eight northern elephant seals in all of the world on Guadalupe Island. They shot seven of them. They needed specimens for the museum and they were on their way to extinction anyhow, so the mindset of the time … And fortunately these animals have recovered, as have many seals and sea lions and whales. And now the Channel Islands contain one of the largest seal and sea lion rookeries anywhere in the world.
This is point bennet on the far western end of the channel islands. However, and you can kind of see these massive 100,000, 150,000, seals and sea lions haul out and occupy these landforms every single year. And this is a modern creation. There are archeological sites all over this point including a large Chumash village, in the middle of this rookery. These animals were not there during the Holocene and they’re probably going to be on off-shore rocks that human hunting and occupation would have scared them away.
The archeological record for sea mammal hunting really ramps up 1,500 years ago and we see with sites with lots of sea mammal remains … And these sites tend to follow what seems to be happening today. That animals are occupying the far western end and lesser populations as we move to the east. However, there’s been major biogeographical changes. Archeological records are dominated by Guadalupes. Modern records are dominated by northern elephant seals. Northern elephant seals are rarely found in archeological records. Guadalupes are abundant in archeological records, rare today in California.
This can create this hauling out on new landforms, can create major management problems, a new population of California sea lions occupying these new landforms that have never been occupied before, in just 12 months cause massive destruction of archeological sites. 1,700 formal artifacts in just this one location being pushed off into these new locations as populations expand.
And then finally, dune building. Dune building is a natural activity that’s been going on pre-human during the Pliocene on the Channel Islands and continues today on the channel islands. But dunes can be viewed as MCLs because human activities like occupying these dunes, and stabilizes those dune faces helps build these dune sheets. And then human burning destabilizes. So you have this sort of human activity promoting stabilization and destabilization processes, creating this sort of dune-like environment for the islands.
All right, thank you.