European Colonialism and the Anthropocene - A View from the Pacific Coast of North America (2013) (15 pages)

G Model ANCENE-12; No. of Pages 15 e10 K.G. Lightfoot et al./Anthropocene xxx (2013) e1-e15 forest ecosystems in the Northeast Pacific (Dayton et al., 1998; Estes and Palmisano, 1974; Simenstad et al., 1978). As voracious predators of various kinds of invertebrate herbivores, sea otters consume large quantities of sea urchins (Strongylocentrotus spp.), abalones (Haliotis spp.), and crabs (Cancer spp.) when they are available. As the primary consumers of kelp vegetation, sea urchins have the capability, if left unchecked, to seriously denude these macroalgae habitats. Thus, the balance between sea otters and sea urchins is animportant factor in shaping the density and distribution of kelp vegetation and its associated fisheries in many North Pacific waters (Dayton et al., 1998; Estes and Duggins, 1995). In some nearshore environments, such as the Aleutian Islands, sizeable sea otter herds will force sea urchins to hide in inaccessible crevices, where they can do little damage to kelp vegetation. However, when sea otter numbers are thinned, this check on sea urchin control is released, potentially resulting in the widespread destruction of near shore kelp communities and the creation of “urchin barrens.” Archeological data suggest that Native Alaskan hunters occasionally overexploited sea otters in prehistory, leading to local pulses when kelp forests and nearshore fisheries were replaced with alternate states comprised mostly of herbivorous invertebrates (Simenstad et al., 1978:404-405). Commercial hunting by the Russians in the late 1700s and early 1800s appears to have produced a similar, but more widespread environmental transformation in coastal waters off the Aleutian Islands (Estes and Palmisano, 1974; Estes et al., 1989:254),. In other Pacific maritime habitats, such as in southern California, the relationship between sea otter overexploitation, sea urchin population expansion, and the destruction of local kelp forests is more complicated (Dayton et al., 1998; Estes and Duggins, 1995:76; Foster et al., 1979). The density and distribution of giant kelp (Macrocystis pyrifera) canopies are influenced by a variety of factors, such as water temperature, substrate type, and light intensity. In addition, there are other significant predators of sea urchins, particularly the California sheephead (Semicossyphus pulcher) and spiny lobsters (Panulirus interruptus), that can maintain checks on urchin populations in the absence of sea otters (Dayton, 1985:230; Dayton et al., 1998; Erlandson et al., 2005; Halpern et al., 2006). Archeological data from the northern Channel Islands indicates that human predation of sea otters in prehistoric times (particularly between 7300 and 3000 BP) resulted in the release of both red abalone (Haliotis rufescens) and sea urchin populations, which may have produced localized sea urchin barrens (Braje et al., 2009, Erlandson et al., 2005, 2009). Similarly, with the extermination of sea otters in the Channel Island waters by the 1850s, there is evidence for an explosion in abalone numbers that was large enough to support a sizeable commercial fishery (Braje et al., 2007). But in both the prehistoric and historic cases, there is no evidence that the giant kelp forests or their complex fisheries, disappeared from local benthic environments with the demise of the sea otters. Our on-going analysis of the consequences of the sea otter extermination in northern California waters indicates a relatively similar pattern as that detected in southern California. Native Californians hunted sea otters for thousands of years for their fur and meat, as archeological findings demonstrate for central and northern California and the San Francisco Bay (Broughton, 1999:137; Jones et al., 2011; Schwaderer, 1992:67-68; Simons, 1992). However, despite sea otters dominating the faunal remains recovered in some archeological deposits, there is no known evidence for extensive prehistoric deposits of sea urchin remains in central or northern California that might indicate urchin barrens as found in the Aleutian Islands (see Jones et al., 2011:257-258). There is evidence for an increase in abalone harvesting in Late Holocene times along the central coast (Jones et al., 2011:257258), but abalones remain relatively rare in _ prehistoric assemblages to the north on the Sonoma County Coast (Kennedy, 2004:233-249, 376-378; Schwaderer, 1992:65). Our archeological study of the Ross Colony indicates a significant transformation took place in local benthic environments in the 1820s and 1830s. We have detected rich deposits (“bone-beds”) in the Native Alaskan Village Site (NAVS) containing significant quantities of large red abalone (H. rufescens) shells and sea urchin (Strongylocentrorus spp.) remains, along with California mussels (Mytilus californianus), chitons (Polyplacophora), small gastropods, fire-cracked rocks, and fish and mammal assemblages (Lightfoot et al., 1997; Schiff, 1997). Constituent analysis of nine bone-bed sediment samples indicate that sea urchins, by weight, make up 6.2-25.6% of the cultural (artifacts, faunal) materials in the deposits. The percentages of the bone bed deposits comprised of both sea urchins and abalone (by weight) rises to between 12.2 and 30.5%, with most hovering around 20% (Lightfoot et al., 1997:363, 380). Similar finds have been found in historic deposits along the North Wall of the Ross stockade (Gonzalez, 2011) and at the Fort Ross Beach Site (FRBS) (Schiff, 1997). The significant quantities of abalones and sea urchin remains in these colonial-age deposits, particularly when compared to their paucity in nearby prehistoric assemblages (Kennedy, 2004:241-244), strongly suggest that the extermination of sea otter herds resulted in a major upsurge of kelp grazing shellfish in local waters. However, even with the significant uptake in herbivorous invertebrates, other lines of archeological evidence indicate that kelp ecosystems were maintained in the local environs. In the same deposits where large quantities of sea urchin and abalone remains were unearthed in the NAVS and FRBS sites, we recovered 1662 elements of fish, of which 92% were identified as cabezon (Scorpaenichthys marmoratus), rockfish (Sebastes spp.), and lingcod (Ophiodon elongatus) (Gobalet, 1997:320, 325). These species are closely associated with nearshore kelp ecosystems in California (Paddack and Estes, 2000). In addition, harbor seals (Phoca vitulina), which also feed on kelp fisheries, are common constituents of these historic deposits (Wake, 1997). In contrast to the archeological findings of Aleutian Island sites, where alternate states of nearshore fishes and harbor seals (serving as proxies for kelp ecosystems) are juxtaposed against sea urchins and limpets (Simenstad et al. 1978:407-409), we find red abalones, sea urchins, limpets, nearshore fish, and harbor seals integrated into the same discrete deposits dating to the 1820s and 1830s (Lightfoot et al., 1997:356-409). In sum, there is little question that the maritime fur trade in the North Pacific had a tremendous impact on maritime environments. Not only did commercial hunting eradicate some marine mammals from local waters, but the RAC’s extensive harvesting of sea otters from Siberia to Alaska and into California may have transformed nearshore benthic habitats, particularly the density and distribution of kelp forest ecosystems and their associated fisheries. However, it appears that the consequences of sea otter hunting varied considerably across space and time from the Aleutian Islands to Southern California (Steneck et al., 2002). Our preliminary study of the eradication of sea otters from northern California waters suggests that a complex spatial pattern probably resulted, in which kelp forest patches became interspersed with spaces dominated by abalone, sea urchins, and other invertebrates. This complexity was observed in the first systematic survey of kelp vegetation in central California in the early 1900s, which was undertaken prior to the “recovery” of local sea otter populations and the commercial fishing of sea urchins in the 1970s (see Dayton et al., 1998:317-319). This survey did not record any evidence for kelp in a few coastal places from San Francisco to Point Sur (McFarland, 1912). However, in other places they found discrete “beds” or patches of giant kelp and bull kelp (Nereocystis luetkeana). In some cases they were quite lush: “beds of these kelps Please cite this article in press as: Lightfoot, K.G., et al., European colonialism and the Anthropocene: A view from the Pacific Coast of North America. Anthropocene (2013), http://dx.doi.org/10.1016/j.ancene.2013.09.002

G Model ANCENE-12; No. of Pages 15 e10 K.G. Lightfoot et al./Anthropocene xxx (2013) e1-e15 forest ecosystems in the Northeast Pacific (Dayton et al., 1998; Estes and Palmisano, 1974; Simenstad et al., 1978). As voracious predators of various kinds of invertebrate herbivores, sea otters consume large quantities of sea urchins (Strongylocentrotus spp.), abalones (Haliotis spp.), and crabs (Cancer spp.) when they are available. As the primary consumers of kelp vegetation, sea urchins have the capability, if left unchecked, to seriously denude these macroalgae habitats. Thus, the balance between sea otters and sea urchins is animportant factor in shaping the density and distribution of kelp vegetation and its associated fisheries in many North Pacific waters (Dayton et al., 1998; Estes and Duggins, 1995). In some nearshore environments, such as the Aleutian Islands, sizeable sea otter herds will force sea urchins to hide in inaccessible crevices, where they can do little damage to kelp vegetation. However, when sea otter numbers are thinned, this check on sea urchin control is released, potentially resulting in the widespread destruction of near shore kelp communities and the creation of “urchin barrens.” Archeological data suggest that Native Alaskan hunters occasionally overexploited sea otters in prehistory, leading to local pulses when kelp forests and nearshore fisheries were replaced with alternate states comprised mostly of herbivorous invertebrates (Simenstad et al., 1978:404-405). Commercial hunting by the Russians in the late 1700s and early 1800s appears to have produced a similar, but more widespread environmental transformation in coastal waters off the Aleutian Islands (Estes and Palmisano, 1974; Estes et al., 1989:254),. In other Pacific maritime habitats, such as in southern California, the relationship between sea otter overexploitation, sea urchin population expansion, and the destruction of local kelp forests is more complicated (Dayton et al., 1998; Estes and Duggins, 1995:76; Foster et al., 1979). The density and distribution of giant kelp (Macrocystis pyrifera) canopies are influenced by a variety of factors, such as water temperature, substrate type, and light intensity. In addition, there are other significant predators of sea urchins, particularly the California sheephead (Semicossyphus pulcher) and spiny lobsters (Panulirus interruptus), that can maintain checks on urchin populations in the absence of sea otters (Dayton, 1985:230; Dayton et al., 1998; Erlandson et al., 2005; Halpern et al., 2006). Archeological data from the northern Channel Islands indicates that human predation of sea otters in prehistoric times (particularly between 7300 and 3000 BP) resulted in the release of both red abalone (Haliotis rufescens) and sea urchin populations, which may have produced localized sea urchin barrens (Braje et al., 2009, Erlandson et al., 2005, 2009). Similarly, with the extermination of sea otters in the Channel Island waters by the 1850s, there is evidence for an explosion in abalone numbers that was large enough to support a sizeable commercial fishery (Braje et al., 2007). But in both the prehistoric and historic cases, there is no evidence that the giant kelp forests or their complex fisheries, disappeared from local benthic environments with the demise of the sea otters. Our on-going analysis of the consequences of the sea otter extermination in northern California waters indicates a relatively similar pattern as that detected in southern California. Native Californians hunted sea otters for thousands of years for their fur and meat, as archeological findings demonstrate for central and northern California and the San Francisco Bay (Broughton, 1999:137; Jones et al., 2011; Schwaderer, 1992:67-68; Simons, 1992). However, despite sea otters dominating the faunal remains recovered in some archeological deposits, there is no known evidence for extensive prehistoric deposits of sea urchin remains in central or northern California that might indicate urchin barrens as found in the Aleutian Islands (see Jones et al., 2011:257-258). There is evidence for an increase in abalone harvesting in Late Holocene times along the central coast (Jones et al., 2011:257258), but abalones remain relatively rare in _ prehistoric

assemblages to the north on the Sonoma County Coast (Kennedy, 2004:233-249, 376-378; Schwaderer, 1992:65). Our archeological study of the Ross Colony indicates a significant transformation took place in local benthic environments in the 1820s and 1830s. We have detected rich deposits (“bone-beds”) in the Native Alaskan Village Site (NAVS) containing significant quantities of large red abalone (H. rufescens) shells and sea urchin (Strongylocentrorus spp.) remains, along with California mussels (Mytilus californianus), chitons (Polyplacophora), small gastropods, fire-cracked rocks, and fish and mammal assemblages (Lightfoot et al., 1997; Schiff, 1997). Constituent analysis of nine bone-bed sediment samples indicate that sea urchins, by weight, make up 6.2-25.6% of the cultural (artifacts, faunal) materials in the deposits. The percentages of the bone bed deposits comprised of both sea urchins and abalone (by weight) rises to between 12.2 and 30.5%, with most hovering around 20% (Lightfoot et al., 1997:363, 380). Similar finds have been found in historic deposits along the North Wall of the Ross stockade (Gonzalez, 2011) and at the Fort Ross Beach Site (FRBS) (Schiff, 1997). The significant quantities of abalones and sea urchin remains in these colonial-age deposits, particularly when compared to their paucity in nearby prehistoric assemblages (Kennedy, 2004:241-244), strongly suggest that the extermination of sea otter herds resulted in a major upsurge of kelp grazing shellfish in local waters. However, even with the significant uptake in herbivorous invertebrates, other lines of archeological evidence indicate that kelp ecosystems were maintained in the local environs. In the same deposits where large quantities of sea urchin and abalone remains were unearthed in the NAVS and FRBS sites, we recovered 1662 elements of fish, of which 92% were identified as cabezon (Scorpaenichthys marmoratus), rockfish (Sebastes spp.), and lingcod (Ophiodon elongatus) (Gobalet, 1997:320, 325). These species are closely associated with nearshore kelp ecosystems in California (Paddack and Estes, 2000). In addition, harbor seals (Phoca vitulina), which also feed on kelp fisheries, are common constituents of these historic deposits (Wake, 1997). In contrast to the archeological findings of Aleutian Island sites, where alternate states of nearshore fishes and harbor seals (serving as proxies for kelp ecosystems) are juxtaposed against sea urchins and limpets (Simenstad et al. 1978:407-409), we find red abalones, sea urchins, limpets, nearshore fish, and harbor seals integrated into the same discrete deposits dating to the 1820s and 1830s (Lightfoot et al., 1997:356-409). In sum, there is little question that the maritime fur trade in the North Pacific had a tremendous impact on maritime environments. Not only did commercial hunting eradicate some marine mammals from local waters, but the RAC’s extensive harvesting of sea otters from Siberia to Alaska and into California may have transformed nearshore benthic habitats, particularly the density and distribution of kelp forest ecosystems and their associated fisheries. However, it appears that the consequences of sea otter hunting varied considerably across space and time from the Aleutian Islands to Southern California (Steneck et al., 2002). Our preliminary study of the eradication of sea otters from northern California waters suggests that a complex spatial pattern probably resulted, in which kelp forest patches became interspersed with spaces dominated by abalone, sea urchins, and other invertebrates. This complexity was observed in the first systematic survey of kelp vegetation in central California in the early 1900s, which was undertaken prior to the “recovery” of local sea otter populations and the commercial fishing of sea urchins in the 1970s (see Dayton et al., 1998:317-319). This survey did not record any evidence for kelp in a few coastal places from San Francisco to Point Sur (McFarland, 1912). However, in other places they found discrete “beds” or patches of giant kelp and bull kelp (Nereocystis luetkeana). In some cases they were quite lush: “beds of these kelps Please cite this article in press as: Lightfoot, K.G., et al., European colonialism and the Anthropocene: A view from the Pacific Coast of North America. Anthropocene (2013), http://dx.doi.org/10.1016/j.ancene.2013.09.002