Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of the Santa Barbara Channel, California, USA

Rick, TC. 2020. Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of the Santa Barbara Channel, California, USA. Open Quaternary, 6: 9, pp. 1–14. DOI: https://doi.org/10.5334/oq.86

RESEARCH PAPER Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of the Santa Barbara Channel, California, USA Torben C. Rick

Terminal Pleistocene to Middle Holocene sea level rise resulted in a number of changes to coastal ecosystems around the world, providing new challenges and opportunities for coastal peoples. In California, glacial to interglacial sea level rise resulted in some reductions in rocky shore kelp forests, but it also resulted in the formation of estuaries. Estuaries were important for terminal Pleistocene peoples in the Santa Barbara Channel region (SBC), a pattern that persisted through the Early to Middle Holocene, and sometimes later. While paleoestuaries appear to have been relatively common along the SBC mainland coast, they were rare to absent on the Channel Islands. The Abalone Rocks Paleoestuary on Santa Rosa Island is the only well documented island estuary. However, questions remain about the size and productivity of this estuary and its importance for human subsistence and settlement relative to the more extensive mainland estuaries. Faunal data from two previously unreported site components and synthesis of shellfish data from other Abalone Rocks sites and similarly aged sites near mainland estuaries illustrate the importance of SBC mainland versus island estuaries. Estuarine shellfish were considerably more abundant at most Early and Middle Holocene mainland sites, with the Abalone Rocks Paleoestuary largely supplementary to rocky shore habitats. At island estuary sites, taxonomic richness was fairly consistent during the Early to Middle Holocene, although diversity and evenness decline slightly through time, with estuarine shellfish largely disappearing from island assemblages prior to 5000 years ago. These data demonstrate the power of archaeological research to evaluate the relationships between past environmental change and human behavior.

Keywords: zooarchaeology; mollusk; human ecology; sea level rise; coastal ecosystems; subsistence

Introduction have been particularly important during the Early and Estuaries have long been important habitats for coastal Middle Holocene (especially ~9000–5000 cal BP) when peoples around the world, with the diversity of estuarine sea level rise resulted in the formation of a series of estu- habitats and organisms supplying people with important aries, including in the Santa Barbara Channel Region food and other resources. For example, estuaries provided (SBC) (Erlandson 1985, 1994, 1997; Glassow 1997, 2020a; shellfish for Neanderthals in the Mediterranean some Reeder-Myers 2014a). As Hildebrandt et al. (2020) note, 42,000 years ago (Stringer et al. 2008) and estuarine and however, modeling of the SBC coastline demonstrates coastal resources may have helped fuel the colonization of that estuaries were not ubiquitous, forming in some areas Sahul (Pleistocene Australia, New Guinea, and Aru Islands) at different times. some 50,000 years ago (Bird et al. 2019). In California and Estuaries were long thought to largely be a feature of elsewhere on the North American Pacific Coast, estuarine mainland coastal California with the offshore Channel resources were also important in early coastal economies Islands lacking such habitats and people focusing subsist- and were part of a broadening of human use of a range ence efforts on rocky intertidal and kelp forest resources of coastal habitats from the terminal Pleistocene through (Erlandson 1994; Rick et al. 2005). We now know that at the Middle Holocene (Erlandson 1994; Erlandson et al. least one estuary (Abalone Rocks) existed on California’s 2019; Graham et al. 2003; Jones & Hadick 2016; Jones et Santa Rosa Island, which is supported by archaeological al. 2019; Masters & Aiello 2007). Estuaries continued to be data, shoreline modeling, and paleoecological research of importance to human subsistence economies through (Anderson et al. 2010; Braje et al. 2019; Cole & Liu 1994; historic times in parts of California, but they appear to Rick et al. 2005). Despite a few studies exploring the importance of estuarine habitats on Santa Rosa Island during the terminal Pleistocene to Middle Holocene, Department of Anthropology, National Museum of Natural History, Smithsonian Institution, Washington, DC, US there has been limited research comparing human use [email protected] of Channel Island estuaries to the estuarine systems on Art. 9, page 2 of 14 Rick: Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of the Santa Barbara Channel, California, USA the adjacent mainland (Erlandson et al. 2019; Jazwa et al. Pleistocene, including on Santa Rosa Island (Erlandson et 2013; Rick et al. 2005, 2006; Wolff et al. 2007). al. 2019; Jazwa et al. 2013; Rick et al. 2005). In this paper, I present new quantified shellfish data Santa Rosa Island currently sits ~44 km offshore and 2 from excavations at two sites dated between ~7450 and is about 217 km in area. The island contained at least 5960 cal BP (CA-SRI-77 and CA-SRI-192) on eastern Santa one estuary in the past, the Abalone Rocks paleoestuary Rosa Island, California that contain a variety of estua- and marsh complex located in the vicinity of Old Ranch rine and rocky coast shellfish species (Figure 1). These and Old Ranch House canyons on the eastern end of the data are placed in the context of contemporary Early island (Cole & Liu 1994; Rick et al. 2005). The Abalone and Middle Holocene sites on Santa Rosa Island and the Rocks Paleoestuary/Marsh produced paleoecological adjacent mainland coast to document the importance of records spanning roughly 7000 calendar years, suggest- estuarine versus outer coast shellfish habitats on island ing marine/estuarine conditions through the Middle and mainland southern California between about 9000 Holocene (Anderson et al. 2010; Cole & Liu 1994). The and 5000 cal BP. These data demonstrate the value of zoo- Abalone Rocks Paleoestuary is unique because it is the archaeological research for informing past environmen- only well documented estuary on the Channel Islands with tal change and human subsistence strategies in complex associated shell middens and human harvest. Other estua- coastal systems. rine habitats likely existed in the terminal Pleistocene and Early Holocene near the now submerged Crescent Bay Context and Background area (which encompasses Abalone Rocks) of Santa Cruz The Santa Barbara Channel region is situated on the south- and Santa Rosa islands, with subbottom profiles raising ern California Coast from Point Conception in the west to the possibility of estuarine deposits in the Santa Cruz Point Mugu in the east. The region is part of the Trans- Channel (see Braje et al. 2019). In addition to the pres- verse Range and trends east-west, rather than north-south ence of an estuary, Old Ranch Canyon is a well-watered like most of the Pacific Coast. The four Northern Channel drainage with abundant freshwater, ranking as the second Islands (NCI) are about 20 to 44 km offshore and mark the most productive Santa Rosa Island drainage because of southern boundary of the SBC. The region is known for its flow, size, resilience and other variables (Jazwa et al. 2016). diverse and productive marine ecosystems and organisms, The NCI have produced evidence of human occupation including kelp forests, rocky shores, sandy beaches, and dated to 13,000 cal BP, with a site near Point Conception estuaries. During the Pleistocene and through about 9000 on the mainland coast dated to ~10,700 cal BP, demon- years ago, the NCI were connected in one large superis- strating some of the earliest coastal settlement in the land known as Santarosae which, although closer to the Americas (Erlandson et al. 2011; Gusick & Erlandson 2019; mainland coast, was always separated by a watergap of at Lebow et al. 2015). The SBC and NCI also contain evidence least 7 km (Braje et al. 2019; Reeder-Myers et al. 2015). of human occupation more or less continuously across Rising sea level from the glacial to interglacial created the Holocene through the early 19th century (Erlandson & numerous estuaries in the Santa Barbara Channel region, Rick 2002; Gamble 2008; Rick et al. 2005). The Chumash which were exploited by people since at least the terminal of the SBC and NCI are well known for their sophisticated

Figure 1: The Santa Barbara Channel region and Northern Channel Islands, showing location of island and mainland sites discussed in the text. Rick: Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of Art. 9, page 3 of 14 the Santa Barbara Channel, California, USA maritime hunting and fishing strategies and use of a vari- A few surface depressions visible in the northern site area ety of marine and terrestrial habitats. On the Channel appear to be the remains of Late Holocene house depres- Islands, marine fishes and shellfish from kelp forest and sions. The site’s Middle Holocene component is exposed rocky intertidal habitats were the focus of human subsist- on a bench in the sea cliff and stratigraphically below the ence strategies since initial colonization through the 19th dense Late Holocene deposits about 1 m below the site century, although people also harvested a wide range of surface (Figure 2). This lower deposit is visible for roughly island terrestrial plants (Braje 2010; Gill & Hoppa 2016). 15 m in the sea cliff and extends for an unknown dis- On the mainland, people appear to have had more bal- tance to the east. The lower midden deposits are roughly anced economies with a greater inclusion of terrestrial 10–20 cm thick and contain scattered pockets of shellfish animal foods (e.g., deer) that were absent on the Channel remains, including estuarine and rocky intertidal taxa and Islands (Erlandson & Rick 2002). lithic artifacts (Rick et al. 2005). Four radiocarbon dates from the site document an occupation at roughly 7450 Materials and Methods years ago and Late Holocene occupation between about Site descriptions and chronology 1150 and 1000 cal BP (Kennett 2005, 2005; Rick 2009; CA-SRI-77 is a multi-component shell midden located on Rick et al. 2005). Radiocarbon dating of a Chione undatella the east side of Becher’s Bay roughly 3–4 km from Aba- shell from the lower component provides a 2 sigma cali- lone Rocks. Dense Late Holocene midden deposits are brated age of 7620–7280 cal BP, centering on 7450 cal BP exposed at CA-SRI-77 in a road cut and along the sea cliff. (Figure 3, Table 1).

UpperComponent

BulkSample2

BulkSample1

Figure 2: Sea cliff exposure at CA-SRI-77 (looking east) showing the lower component and location of Bulk Samples 1 and 2 and the Upper Component deposits dated to the Late Holocene. Photo by T. Rick, 2003.

R_Date SRI-192-OS-54919

R_Date SRI-192-OS-51578

R_Date SRI-192-B-183138

R_Date SRI-77-B-180926

8500 8000 7500 7000 6500 6000 5500

Calibrated date (calBP) Figure 3: Oxcal plot of the 2 sigma calibrated calendar age for Middle Holocene radiocarbon dates from CA-SRI-77 and CA-SRI-192 presented in Table 1 (Bronk Ramsey 2009). Art. 9, page 4 of 14 Rick: Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of the Santa Barbara Channel, California, USA

Table 1: Radiocarbon data from Middle Holocene components at CA-SRI-192 and CA-SRI-77.

Site Provenience Lab Numbera Material d13C 13C/12C Calibrated Age Adjusted Age BP (2 Sigma) b CA-SRI-192 Unit 1, 10–12 cmbs OS-54919 S. nuttalli 0.79 5670 ± 35 5890–5660 Unit 1, 60 cmbs OS-51578 O. lurida 1.34 5990 ± 40 6260–6000 Probe, southern site margin B-183138 O. lurida — 6440 ± 70 6800–6430 CA-SRI-77 Basal midden, sea cliff B-180926 C. undatella — 7220 ± 90 7620–7280 a OS = National Ocean Sciences AMS Facility; B = Beta Analytic Inc. b All shell dates were calibrated with a DR of 261 ± 21 years for all shell samples (Jazwa et al. 2012). 13C/12C ratios were determined by the radiocarbon labs. Calibrations were made using the Marine13 calibration Curve (Reimer et al. 2013) and OxCal 4.3 calibration program (Bronk Ramsey 2009). The date from CA-SRI-77 was obtained from Rick et al. (2005) and the dates from CA-SRI-192 were obtained from Rick (2009).

Figure 4: CA-SRI-192 looking west with the site covering most of the area in the center right of the photo, showing approximate location of the Middle Holocene midden exposure at Unit 1/1A and the Upper Component midden dated to the Late Holocene. Photo by T. Rick, 2005.

CA-SRI-192 is located on a gently sloping hill overlook- CA-SRI-192 represent a roughly 1000 to 1500 year period ing the Abalone Rocks Marsh. Shell midden deposits sit on of time centered between 7450 and 5960 cal BP. top of the hill and down slope, with a small rockshelter also located on site (Figure 4). Our work at the site dem- Field methods onstrates that, like CA-SRI-77, the site has at least two com- In 2003, two 15 L bulk samples (Bulk Samples 1 and 2) ponents, one containing mostly Mytilus californianus shell, were excavated in intact midden deposits exposed in the as well as a single piece fishhook on top of the plateau and sea cliff at CA-SRI-77. These samples were spaced about 3 another with estuarine taxa located downslope (Rick 2019; m apart on the sea cliff and excavated by hand and trowel Rick et al. 2005). Two radiocarbon dates obtained from using measured buckets to obtain volume. All samples shells collected in an auger hole excavated on top of the were screened over 1/16-inch mesh in the field, with hill demonstrate a Late Holocene occupation around 2500 1/8-inch residuals analyzed for this study. Data from Bulk cal BP (Rick 2019). Three additional radiocarbon dates Sample 1 were presented in Rick et al. (2005), but the data were obtained from the estuarine midden and provide a from Bulk Sample 2 have not been reported. 2 sigma range of 6800 to 5660 cal BP (Figure 3, Table 1). Excavations at CA-SRI-192 were conducted in 2005. However, the shellfish samples reported here come from Unit 1/Unit 1a was excavated as two 50 L bulk samples Unit 1, with two dates that suggest a more constrained (100 L total volume) from a 50 × 50 cm area in archae- occupation between 6260 and 5660 cal BP, centering on ological deposits located in a small bench on the hill. 5960 cal BP. Collectively, the deposits from CA-SRI-77 and Because of the eroding nature of the deposits and lack of Rick: Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of Art. 9, page 5 of 14 the Santa Barbara Channel, California, USA stratigraphic variation, these bulk samples were collected Table 2: Shellfish remains from CA-SRI-77, Bulk Samples 1 from the same area down to a depth of 60 cm, with Unit and 2 combined (see Table S2 for individual units). 1 representing the upper 30 cm and Unit 1a representing the lower 30 cm. These midden deposits were extremely Taxon Category Wt. (g) % Wt. MNI % MNI dense and all residuals were poured over 1/8-inch mesh (g) in the field. The Unit 1/1a samples were processed sep- Bivalves arately in case of any variation in constituents noted in Chione californiensis* 77.2 6.5 5 5.6 the midden. Two augers were also excavated in the Late Chione sp.* 45.1 3.8 1 1.1 Holocene deposits at the site, demonstrating a midden dominated by Mytilus californianus with no estuarine Chione undatella* 206.3 17.3 12 13.5 shell to a depth of about 80 cm (Rick 2009, 2019). Chionista fluctifraga* 18.9 1.6 1 1.1 Mytilus californianus 275.8 23.1 32 36.0 Laboratory procedures All excavated samples were returned to the lab for pro- Ostrea lurida* 188.1 15.7 11 12. cessing and analysis. Residuals were water screened, with Protothaca staminea* 3.6 0.3 1 1.1 1/8-inch samples forming the focus of research. Students Septifer bifurcatus sorted the 1/8-inch residuals into general categories of 2.0 0.2 — — shellfish, fish, mammal, bird, other vertebrate remains, Clam undif. 39.0 3.3 5 5.6 artifacts, botanical remains, etc. Shellfish dominated the Crustaceans assemblages at both sites, with only trace amounts of vertebrate faunal remains, which is generally consistent Balanus spp. 5.2 0.4 — — with other Early to Middle Holocene sites in the Abalone Brachyura (Crab undif.) 7.9 0.7 — — Rocks area (Jazwa et al. 2013; Rick et al. 2005). For the Pollicipes polymerus 0.1 <0.1 1 1.1 two 15 L samples from CA-SRI-77, all 1/8-inch and larger Gastropods materials were completely analyzed. Given the large volume of materials from CA-SRI-192, all 1/4-inch materials Crepidula sp. 0.3 <0.1 1 1.1 were completely processed and a random 25% sample Euspira lewisii* 45.5 3.8 3 3.4 by weight of 1/8-inch residuals was analyzed. All faunal Haliotis cracherodii remains were identified using comparative collections 3.1 0.3 1 1.1 at Southern Methodist University and the Smithsonian Haliotis rufescens 219.5 18.4 2 2.3 Institution, with taxonomy following the Integrated Taxo- Lottia gigantea 1.8 0.2 1 1.1 nomic Information System (www.itis.gov). Habitat infor- Megastraea undosa mation for shellfish follows Morris et al. (1980) with those 0.8 0.1 1 1.1 taxa from estuarine habitats starred in Tables 2 and 3. Nucella sp. 1.9 0.2 1 1.1 All faunal materials were weighed in grams and MNI Olivella biplicata 2.9 0.3 3 3.4 were calculated using sided hinges for bivalves and spires for gastropods. Following previous shellfish syntheses in Tegula funebralis 5.1 0.4 3 3.4 the region, we focus on raw weights to explore the abun- Gastropod undif. 1.8 0.2 3 3.4 dance and significance of various taxonomic categories Polyplacophora (Braje et al. 2011, 2012). While several studies have shown Cryptochiton stelleri the strengths and weaknesses of various approaches to 6.3 0.5 1 1.1 quantifying archaeological shellfish remains (see Giovas Chiton undif. 4.7 0.4 — — 2009), the use of weight allows for broad regional com- Other parison across a number of other studies on Santa Rosa Island and the adjacent mainland. Because of a lack of Nacre undif. 14.9 1.2 — — stratigraphic variation and limited differences in constitu- Marine shell undif. 18.5 1.6 — — ents between the two bulk samples from CA-SRI-77 and Total 1195.8 — 89 — the two contiguous units at CA-SRI-192, these samples have been combined for each site, with data for the sepa- * Denotes species commonly found in estuaries. Protothaca, rate units available in Tables S1 and S2. Euspira, and Saxidomus can also occasionally be found in Changes in taxonomic richness (number of taxo- outer coast (Morris et al. 1980). nomic categories), diversity, and evenness at CA-SRI-77, CA-SRI-192, and other estuary sites near Abalone Rocks of taxonomic categories (Reitz & Wing 2008: 111–112). (Erlandson et al. 2019; Jazwa et al. 2013; Rick et al. The Shannon-Weaver function provides a quantitative 2005, 2006; Wolff et al. 2007) were estimated using the means to evaluate how diverse and evenly distributed a Shannon-Weaver diversity (H’) and evenness (V’) function: particular shellfish assemblage is, which can help further

H’ = –∑ (pi) (loge pi), where pi is the relative abundance evaluate environmental change and human shellfish col- (weight) of an individual shellfish taxonomic category lecting strategies across space and through time. To fur- divided by the total weight of all the taxonomic cat- ther understand the importance of estuarine compared to egories and V’ = H’/loge S, where S is the total number outer coast shellfish on the adjacent mainland and Santa Art. 9, page 6 of 14 Rick: Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of the Santa Barbara Channel, California, USA

Table 3: Shellfish remains from CA-SRI-192, Unit 1/1A Rosa Island, we use % of total shell weight from a range Combined (see Table S1 for individual units). of island and mainland sites (Figure 1), with mainland data relying on recent synthesis and recalculations by Taxonomic Category Wt. (g) %Wt. MNI %MNI Hildebrandt et al. (2020). (g) Bivalves Results Chione californiensis* 24.1 0.1 1 0.1 A total of ~1.2 kg of shellfish remains was recovered from the 1/8-inch bulk samples at CA-SRI-77 (Table 2). At least Chione sp.* 13.5 0.1 21 different marine shellfish were identified. The shellfish Chione undatella* 24.6 0.1 1 0.1 assemblage is relatively evenly distributed between estua- Chionista fluctifraga* 196.7 0.8 10 0.7 rine (49.7%) and outer coast/rocky shore (50.3%) species. Two rocky shore species, Mytilus californianus (23.1%) and Mytilus californianus 17891.0 71.7 1022 67.9 Haliotis rufescens (18.4%) dominate the shellfish weight, Ostrea lurida* 2962.6 11.9 67 4.5 followed by Chione undatella (17.3%), Ostrea lurida (15.7%), and Chione californiensis (6.5%) from estuarine Protothaca sp.* 4.1 0.0 1 0.1 habitats. All other shellfish tend to be minor contributors Septifer bifurcatus 18.1 0.1 25 1.7 at less than 4% of the shellfish weight. Vertebrate remains Saxidomus nuttalli* 713.2 2.9 14 0.9 were rare in this sample, with just 25 fragmentary mammal bones, 22 undifferentiated bones, 1 Semicossyphus Crustaceans pulcher (California sheephead) tooth, and 3 bird bones. Brachyura (Crab undif.) 11.4 0.1 — — The assemblage from CA-SRI-192 contained nearly 25 kg Cirripedia (Barnacle 795.7 3.2 — — of shellfish from the 1/8-inch remains in Unit 1/1A (Table undif.) 3, Table S2). This includes some 25 different marine shellfish and land snail remains. In contrast to the relatively Pollicipes polymerus 8.8 <0.1 — — even distribution between estuarine and open coast sam- Echinoderms ples at CA-SRI-77, open coast/rocky shore taxa dominate at Strongylocentrotus sp. 147.7 0.6 — — CA-SRI-192 with 83.7% of the weight, with estuarine shell- Gastropods fish accounting for 16.3%. Mytilus californianus makes up the majority of the assemblage (71.7% by weight), followed Conus californicus 1.2 <0.1 — — by Ostrea lurida (11.9% of weight), Cirripedia (barnacles, Crepidula sp. 23.8 0.1 77 5.1 3.2%), Saxidomus nuttalli (2.9%), Haliotis rufescens (2.5%), Megastraea undosa (1.3%), and all other species contribut- Euspira lewisii* 58.4 0.2 3 0.2 ing less than 1%. Vertebrate remains were also relatively Fissurella volcano 8.7 <0.1 17 1.1 limited in the CA-SRI-192 assemblage, with mostly frag- Haliotis cracherodii 26.3 0.1 2 0.1 mented and undiagnostic bones. This includes 122 mammal bones, 11 bird bones, 16 fish bones, and 3 Embiotocid Haliotis rufescens 627.9 2.5 5 0.3 (surfperch) bones in Unit 1/1a. Megastraea undosa 316.4 1.3 6 0.4 Taxonomic richness and Shannon-Weaver diversity and Norrisia norrisi 33.2 0.1 1 0.1 evenness values from CA-SRI-77, CA-SRI-192, and four other estuarine site components from the Channel Islands Olivella biplicata 14.9 0.1 18 1.2 document some temporal variation (Figure 5; Table S3). Tegula funebralis 122.5 0.5 34 2.3 The richness values are somewhat consistent through time Vermetidae 15.0 0.1 — — between 20–24 species, with a low of 10 at CA-SRI-84/187 (Rick et al. 2005) and a peak of 44 at CA-SRI-666 (Erlandson Gastropod undif. 7.8 <0.1 18 1.2 et al. 2020a). The low value may be a result of small sam- Limpet undif. 10.3 <0.1 181 12.0 ple size, while the higher value at CA-SRI-666 is influenced somewhat by analytical differences, with many species Polyplacophora of limpet, gastropod, and chiton identified to species at Chiton sp. 12.7 0.1 2 0.1 CA-SRI-666, but only identified to more general taxonomic Other categories in the other studies. Diversity values range from 0.7 to 1.9 and evenness from 0.19 to 0.64, with CA-SRI-77 Nacre undif. 853.5 3.4 — — having the highest values for each category and the other Marine shell undif. 5.1 <0.1 — — sites generally clustering closer together. This is reflected Total 24948.9 — 1505 — in the relatively even distribution of shellfish from open coast and rocky shore habitats at CA-SRI-77 whereas most Land snail 1.4 — 2 — other sites tend to be skewed by a much higher abundance * Denotes species commonly found in estuaries. Protothaca, of open coast compared to estuarine species. Euspira, and Saxidomus can also occasionally be found in When placed in the context of 5 additional site com- outer coast (Morris et al. 1980). ponents with estuarine harvest on Santa Rosa Island, and Rick: Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of Art. 9, page 7 of 14 the Santa Barbara Channel, California, USA

Figure 5: Taxonomic richness, diversity, and evenness for six archaeological sites on eastern Santa Rosa Island with estuarine shellfish collecting from 8000–5960 cal BP (see Table S3 for raw data and references).

12 site components from the adjacent mainland, the data are above 90% estuarine shellfish and four others are 59% from CA-SRI-77 and CA-SRI-192 inform broader patterns or higher. of the importance of estuarine shellfish compared to the outer coast between about 9000 and 5000 years ago on Discussion the mainland and 8000 and 5900 years on the islands Archaeologists working in California have long been inter- (Figure 6, Tables S3 and S4). These data illustrate that ested in the importance of estuaries for human subsist- on Santa Rosa Island between 4.1% and 49.7% of shell- ence and settlement, beginning with early research on San fish come from estuarine habitats. Although the 8000 Francisco Bay shell middens and more recently by investi- year old component at CA-SRI-666 is only 6.5% estuarine gating the importance of estuaries for driving early human shellfish, the other two early sites, SRI-84/187 and SRI- (Paleocoastal) settlement and subsistence (Erlandson et al. 77 have 33.9%, and 49.7%, respectively, with percent- 2019; Jones et al. 2019; Reeder-Myers 2014a). Jones et al. ages dropping quickly through time after this. These data (2019: Table 1.1, Figure 1.2) list 30 estuaries, bays, lagoons, stand in sharp contrast to the 12 mainland assemblages, and paleoestuaries from San Diego/Tijuana in the south where estuarine shellfish make up between 16.5% and to Del Norte in the far north of California, with occupa- 96.5% estuarine shellfish (Figure 6). Five of the 12 sites tion spanning the Holocene. However, the timing and Art. 9, page 8 of 14 Rick: Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of the Santa Barbara Channel, California, USA

100 90 80 70

llfish 60 She 50

% of 40 IslandEstuarine 30 ShellfishAbundance 20 10 0 8000 7960 7450 6410 6200 5980 5960

CalendarYearsBP

100

70 h 60 Shellfis

% of 40

20 MainlandEstuarine ShellfishAbundance 10

0 8880 8270 7910 7910 7870 7240 7090 7080 5610 5000 4900 CalendarYearsBP Figure 6: Abundance of estuarine shellfish as a percentage of total shell weight (excluding terrestrial and undifferentiated shell) at island (top) and mainland (bottom) sites from ~8000–5960 cal BP on the islands and ~8880–4900 cal BP on the mainland (see Tables S3 and S4 for raw data and references). intensity of human focus on estuarine resources varied Island, especially in the now submerged Crescent Bay considerably by location and in relation to major climatic (Braje et al. 2019). events, such as sea level rise during the Pleistocene/Holo- At the other end of the spectrum, Minas (2017) docu- cene transition that was crucial in the formation of many mented trace amounts of Ostrea lurida and Saxidomus estuaries in the SBC, including Abalone Rocks (Erlandson nuttalli in the Late Holocene shell midden CA-SRI-670. 1994, 1997; Glassow 2020a; Jazwa et al. 2013; Jones et al. Midden samples demonstrate that Mytilus californianus 2019; Reeder-Myers 2014a; Rick et al. 2005). and other rocky intertidal shellfish dominate the assem- Radiocarbon dating of archaeological sites on eastern blage, with estuarine shell comprising less than 1% of the Santa Rosa Island demonstrates that Abalone Rocks was shellfish assemblage by weight. A direct date on an oyster a focus of human settlement and subsistence between shell from this deposit ranges from ~935–730 cal BP, rais- about 8000–5000 years ago (Rick 2009), which roughly ing the possibility that there was an estuary somewhere on corresponds with the timing of estuarine conditions doc- the island at this late date (Minas 2017). S. nuttalli can be umented in paleoecological cores (Anderson et al. 2010; found in sheltered beaches on the outer coast, but oysters Cole & Liu 1994). Work at two sites on Santa Rosa Island are generally only found in bays and estuaries (Morris et (CA-SRI-708 and CA-SRI-670) indicates that Abalone al. 1980). Given that these species occur in trace amounts Rocks or another yet to be documented estuary was uti- they could have also been traded in from the mainland, lized by people on the island both well prior to the 8000 but testing at other sites in the area is needed to deter- years ago and perhaps considerably later than 5000 years mine if estuarine shellfish were present and exploited in ago (Erlandson et al. 2019; Minas 2017). These two sites the Late Holocene. are located near Water Canyon on the north coast of Calculation of taxonomic richness, diversity, and even- Santa Rosa Island about 3 km west of CA-SRI-77 and ~7 ness from Abalone Rocks sites and estuarine versus open km from the current Abalone Rocks Marsh. CA-SRI-708 is coast shellfish abundance from Santa Rosa Island and main- a shell midden that appears to be dominated by Mytilus land sites supplies a means to evaluate the importance of californianus, but with smaller amounts of estuarine shell. estuaries to Early and Middle Holocene peoples through- Three dates on Chione undatella shells document its age out the SBC. Data on taxonomic richness from Abalone around 11,300–10,850 cal BP (Erlandson et al. 2019). No Rocks sites are generally consistent, suggesting a similar quantified data are available from this site, but these data suite of shellfish that were harvested with two exceptions suggest that estuaries were important for some of the (CA-SRI-84/187 and CA-SRI-666) that may be from sam- earliest peoples to live on the Channel Islands, though it ple size and analytic procedures, rather than human diet is unclear precisely where these shellfish may have been (Figure 5). The biological diversity of the five assemblages obtained and raises the possibility of other estuaries calculated using the Shannon-Weaver function is fairly low beyond Abalone Rocks and including western Santa Cruz in the earliest two assemblages, with a peak in diversity Rick: Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of Art. 9, page 9 of 14 the Santa Barbara Channel, California, USA and evenness at the 7450 cal BP occupation of CA-SRI-77 the Milling Stone Horizon on the Channel Islands com- followed by a decline through the two latest estuary compared to the mainland coast where the Milling Stone ponents at about 5960 cal BP. This decline later in time may Horizon was widespread (Erlandson 1994). As Erlandson relate to the closure of the estuary with people focusing (1991) noted, Early Holocene Milling Stone peoples on the on the rich Mytilus californianus beds available through- SBC mainland often took advantage of estuarine shellfish out these site occupations. Whatever the case, regardless in tandem with seeds and other plant foods that could be of time period or site location, M. californianus is the most processed with manos and metates identified at early sites. abundant taxon at most Abalone Rocks sites, demonstrat- Manos and metates are rare and the Millingstone Horizon ing that the estuary was likely never more than an impor- is absent from the NCI, with early people instead focus- tant supplemental focus of island human diets. In this ing largely on geophytes (corms) that required different sense, the presence of an estuary on eastern Santa Rosa processing methods, including at Abalone Rocks sites (see Island added to the attractiveness of the area for human Erlandson et al. 2020a; Gusick 2012, 2013; Gusick and settlement, providing a range of habitats for human sub- Erlandson 2019). These differences are important and show sistence (kelp forest, rocky intertidal, open sandy coast, just how distinct early islanders and mainlanders were in etc.), but was not the sole reason for settlement (Jazwa et terms of basic subsistence strategies and technologies. al. 2013; Rick et al. 2005). What about changes in individual shellfish species and SBC archaeologists have long recognized the importance their relation to potential evolution and the development of estuaries in mainland coastal California throughout the of the Santa Rosa Island estuary? Colten (1989) argued Holocene, including some estuaries that may have only that increases in Chione spp. relative to Saxidomus nuttalli persisted during the Early to Middle Holocene (Erlandson may indicate an increase in mudflats in the Goleta Slough. 1991, 1994, 1997; Glassow 1997, 2020b; Reeder-Myers This suggestion was revisited by Hildebrandt et al. (2020), 2014a). Mainland estuaries like the Goleta Slough provided Erlandson et al. (2020b), and Glassow (2020b), with S. nut- shellfish and other resources throughout the Holocene, talli and Protothaca spp. representing an immature estu- with peak abundance often occurring in some Late ary, whereas Chione spp. and, to an extent, Ostrea lurida Holocene or even Historic period middens (Glassow 2020a; may represent a more mature estuary. Comparison of the Hildebrandt et al. 2020). Beyond the Goleta Slough, most abundance of the four major estuarine shellfish genera mainland SBC estuaries, particularly those in the western at seven Abalone Rocks components provides a means to Santa Barbara Coast were most productive during the Early test potential changes in habitat in the Santa Rosa Island to Middle Holocene as evidenced by several sites with estu- estuary (Figure 7, Table S5). These data document fluctua- arine shellfish through about 5000 years ago that then pre- tions in the importance of various taxa through time. S. cipitously decline or disappear (Erlandson 1997). Decades nuttalli reaches peak abundance in the oldest two assem- of research has detailed this pattern on the mainland, blages dated to roughly 8000 cal BP at CA-SRI-666 and which has often stood in contrast to the Channel Islands, CA-SRI-84/187, with a decline at 7450 cal BP and generally where only one estuary has currently been documented lower abundance through about 5900 years ago, although and its significance was still relatively poorly documented. one site demonstrates about 50% S. nuttalli around 6200 Quantified data from seven island site components and 12 cal BP. O. lurida and Chione spp. are generally more abun- on the mainland coast demonstrate that, for the most part, dant in middens after about 7500 years ago. Protothaca the more extensive estuarine systems on the mainland spp. which can be found in a range of habitats is generally were far more important to human subsistence than they low in all sites, but peaks in one of the latest assemblage were on Santa Rosa Island (Figure 6). Even on the western at 5980 cal BP. It is conceivable that these patterns reflect Santa Barbara Coast, where estuaries were likely never as a shift to a more mature estuarine environment ~7450 cal productive as the Goleta Slough, estuarine shellfish abun- BP. Alternatively, they could also represent more localized dance in all four Early Holocene site components there focus on obtaining shellfish from specific habitats. exceed 90%, whereas only one site on Santa Rosa Island Complicating perspectives on changing Abalone Rocks even approaches 50% with the rest at 33% or substan- Estuary conditions is that CA-SRI-708 demonstrates estua- tially lower. Adding to this, is the fact that some mainland rine shellfish exploitation by ~11,000 years ago, including estuarine assemblages also contain a wider range of spe- Chione spp. and O. lurida (Erlandson et al. 2019). While cies that inhabit estuaries and in some cases other habitats quantified data are not available from this site, these data (Argopecten aequisulcatus [scallop], Cerithedeopsis califor- provide preliminary support for a terminal Pleistocene nica [horn shell], and Macoma nasuta [bent-nosed clam]) mature estuary on Santa Rosa Island, perhaps at Crescent that, to my knowledge, have yet to be identified in Abalone Bay (Braje et al. 2019). The 8000–6000 year old sites Rocks island assemblages in any significant abundance (see described here all post-date the breakup of Pleistocene Erlandson et al. 2020b; Glassow 2020b). These data illus- Santarosae Island by over 1000 years, and likely represent trate some important differences between Early to Middle the exploitation of Abalone Rocks. Currently, there is a Holocene island and mainland people, with estuaries being gap between CA-SRI-708 (~11,000 cal BP) and CA-SRI-666 a significant focus of subsistence on the mainland, and and CA-SRI-84/187 (~8000 cal BP) of roughly 3000 years islanders generally focusing on the rich rocky intertidal and without any known estuary sites. Future research should kelp forest habitats for more than 10,000 years (Braje 2010; explore the possibility of sites that could fill this gap and Kennett 2005). help understand the changing coastal paleogeography of Another important difference between Early Holocene the dynamic eastern Santa Rosa and western Santa Cruz mainland and island communities is the apparent lack of Island landscapes. Art. 9, page 10 of 14 Rick: Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of the Santa Barbara Channel, California, USA

Figure 7: Changes in the abundance of estuarine shellfish at seven Abalone Rocks Site Components. These data com- pare just the abundance of estuarine shellfish taxa, showing fluctuations in each taxa through time relative to one another. Note widespread variation in the abundance in specific taxa through time. See Table S5 for raw data.

Conclusions ecosystems, and sheltered waters were attractive areas Estuaries were an important component of diverse Early around the world that, along with other coastal ecosys- and Middle Holocene subsistence strategies on the SBC tems, may have helped fuel the Late Pleistocene spread of mainland Coast and Channel Islands. Rocky intertidal people along the Pacific Coast of the Americas and the col- shellfish dominate at most sites on the Channel Islands, onization of Sahul (Bird et al. 2019; Erlandson et al. 2019). but the Abalone Rocks Estuary/Marsh provided an impor- Estuaries are dynamic and strongly influenced by climate tant source of food and allowed people access to a diverse change, particularly changes in sea level, freshwater input, array of resources in the eastern Santa Rosa Island area. and infilling with alluvium. The significance of estuar- People opportunistically exploited Abalone Rocks Marsh ies globally cannot be overstated, with sites across the and then, after its closing sometime around 5000 years Holocene documenting human use of estuarine habitats ago, people shifted to other resources, especially rocky from Britain to Northumberland, Canada, the Chesapeake shore and kelp forest foods (Jazwa et al. 2013; Rick et al. Bay, United States of America, Southwest Mexico, coastal 2005). People also shifted to Tivela stultorum at nearby Peru, Queensland, Australia, Tanzania, Madagascar, and CA-SRI-209 obtained from open coast sandy beaches Thailand and broader Southeast Asia (Bell & Neumann ~4730–4360 cal BP, but trace amounts of Tivela stulto- 1997; Beresford-Jones et al. 2018; Douglass 2017; Higham rum have been identified at an Early Holocene site in the 2017; Lelièvre 2017; Pollard 2008; Reeder-Myers et al. nearby Carrington Point area and a few other early and 2016; Smith & McNiven 2019; Voorhies 2004). The data later sites on San Miguel and Santa Cruz islands (Reeder- from Abalone Rocks and the SBC add to these global pat- Myers 2014b; Rick & Eliot 2013; Thakar 2011). Similar terns, demonstrating that estuaries were important for changes in habitat exploitation are evident in some main- human settlement and subsistence in the Holocene on all land sites too, documenting the wider pattern of peo- continents except Antarctica, and illustrating the impor- ple adjusting subsistence pursuits and decision-making tance of archaeological research to evaluate long-term related to changing environments throughout the SBC environmental change in dynamic coastal environments. (Reeder-Myers 2014a; Vellanoweth and Erlandson 2004). In this case, the most apparent changes are shifts between Data Accessibility Statement rocky shore, surfswept sandy beach, and estuarine habi- All data used for this study are presented in the main text tats that manifested at different times in different places, or the online supplement. The CA-SRI-77 and CA-SRI-192 often correlating with broader environmental changes collections are housed at the Department of Anthropol- (e.g., El Niño frequency, sea level rise, etc.)(see Masters & ogy, Santa Barbara Museum of Natural History under Aielo 2007). Accession CHIS-442. The data from Santa Rosa Island and the SBC mainland highlight the global significance of estuaries in the human Additional Files past. The high biodiversity, mix of different organisms and The additional files for this article can be found as follows: Rick: Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of Art. 9, page 11 of 14 the Santa Barbara Channel, California, USA

• Table S1. Shellfish remains from CA-SRI-77, Bulk Bradshaw, CJA. 2019. Early human settlement of Samples 1 and 2. DOI: https://doi.org/10.5334/ Sahul was not an accident. Scientific Reports, 9: 8220. oq.86.s1 DOI: https://doi.org/10.1038/s41598-019-42946-9 • Table S2. Shellfish remains from CA-SRI-192, Unit 1. Braje, TJ. 2010. Modern Oceans, Ancient sites: Archaeology DOI: https://doi.org/10.5334/oq.86.s2 and Marine Conservation on San Miguel Island. Salt • Table S3. Abundance of estuarine and outer coast Lake City: University of Utah Press. shellfish and taxonomic richness, diversity, and even- Braje, TJ, Maloney, JM, Gusick, AE, Erlandson, JM, ness for Santa Rosa Island estuary sites. Used to cre- Nyers, A, Davis, L, Gill, KM, Reeder-Myers, L ate Figures 5 and 6. DOI: https://doi.org/10.5334/ and Ball, D. 2019. Working from the known to the oq.86.s3 unknown: linking the subaerial archaeology and the • Table S4. Abundance of estuarine versus outer coast submerged landscapes of Santarosae Island, Alta shellfish in Early and Middle Holocene mainland San- California, USA. Open Quaternary, 5(1): 10. DOI: ta Barbara Channel Sites. Used to create Figure 6. DOI: https://doi.org/10.5334/oq.66 https://doi.org/10.5334/oq.86.s4 Braje, TJ, Rick, TC and Erlandson, JM. 2012. A trans- • Table S5. Percentages of major estuarine shellfish Holocene historical ecological record of shellfish genera identified in Abalone Rocks sites. Used to cre- harvesting on the northern Channel Islands. Qua- ate Figure 7. DOI: https://doi.org/10.5334/oq.86.s5 ternary International, 264: 109–120. DOI: https:// doi.org/10.1016/j.quaint.2011.09.011 Acknowledgements Braje, TJ, Rick, TC, Erlandson, JM and Willis, LM. 2011. Fieldwork was supported by the National Park Service. I Shellfish and the Chumash: marine invertebrates and thank Deana Dartt, Katie Pearson, and Kelly Shaw for help emergent complexity on Late Holocene San Miguel with fieldwork at CA-SRI-77 and Kevin Pemberton, John Island, California. North American Archaeologist, 32: Robbins, and Chris Wolff for assistance at CA-SRI-192. Sev- 269–292. DOI: https://doi.org/10.2190/NA.32.3.c eral students at Southern Methodist University and the Bronk Ramsey, C. 2009. Bayesian analysis of radiocarbon Smithsonian Institution helped sort and process samples dates. Radiocarbon, 51: 337–360. DOI: https://doi. in the lab. Danielle Duguid and Jennifer Eliot helped pro- org/10.1017/S0033822200033865 duce catalogs and tables of the archaeological shellfish. Cole, KL and Liu, G. 1994. Holocene paleoecology of My understanding of the archaeology of California estuar- an estuary on Santa Rosa Island, California. Qua- ies has been greatly enhanced by conservations with Todd ternary Research, 41: 326–335. DOI: https://doi. Braje, Jon Erlandson, Mike Glassow, John Johnson, Doug org/10.1006/qres.1994.1037 Kennett, Leslie Reeder-Myers, and René Vellanoweth. Colten, RH. 1989. Prehistoric shellfish exploitation I thank the editors of Open Quaternary and two anony- around the Goleta Lagoon, California. Journal of Cal- mous reviewers for comments that greatly improved ifornia and Great Basin Anthropology, 11: 203–214. this manuscript. Any errors of fact in this manuscript are Douglass, K. 2017. The diversity of Late Holocene shell- solely mine. fish exploitation in Velondriake, Southwest Mada- gascar. Journal of Island and Coastal Archaeology, Competing Interests 12: 333–359. DOI: https://doi.org/10.1080/15564 The author has no competing interests to declare. 894.2016.1216480 Erlandson, JM. 1985. Early Holocene subsistence and set- References tlement in relation to coastal paleogeography: evi- Anderson, RS, Starratt, S, Brunner Jass, RM and Pinter, dence from CA-SBA-1807. Journal of California and N. 2010. Fire and vegetation history on Santa Rosa Great Basin Anthropology, 7: 103–109. Island, Channel Islands, and long-term environ- Erlandson, JM. 1991. Shellfish and seeds as optimal mental change in southern California. Journal of resources: Early Holocene subsistence on the Quaternary Science, 25: 782–797. DOI: https://doi. Santa Barbara Coast. In: Erlandson, J and Colten, R. org/10.1002/jqs.1358 (eds.), Hunter-gatherers of Early Holocene Coastal Bell, M and Neumann, H. 1997. Prehistoric intertidal California, 89–101. Los Angeles: Cotsen Institute of archaeology and environments in the Severn Estu- Archaeology, University of California. ary, Wales. World Archaeology, 29: 95–113. DOI: Erlandson, JM. 1994. Early Hunter-Gatherers of the https://doi.org/10.1080/00438243.1997.9980365 California Coast. New York: Plenum. DOI: https:// Beresford-Jones, D, Pullen, A, Chauca, G, Cadwallader doi.org/10.1007/978-1-4757-5042-3 L, García, M, Salvatierra, I, Whaley, O, Vásquez, Erlandson, JM. 1997. The Middle Holocene on V, Arce, S, Lane, K and French, C. 2018. Refining the eastern Santa Barbara Coast. In: Erland- the Maritime Foundations of Andean Civilization: son, J and Glassow, M (eds.), The Archaeology of how plant fiber technology drove social complexity the California Coast During the Middle Holocene, during the Preceramic Period. Journal of Archaeolog- 91–110. Los Angeles: Cotsen Institute of Archaeol- ical Method and Theory, 25: 393–425. DOI: https:// ogy, University of California. doi.org/10.1007/s10816-017-9341-3 Erlandson, JM, Rick, TC, Ainis, AT, Braje, TJ, Gill, KM Bird, MI, Condie, SA, O’Connor, S, O’Grady, D, and Reeder-Myers, L. 2019. Late Pleistocene estuar- Reepmeyer, C, Ulm, S, Zega, M, Saltre, F and ies, palaeoecology, and humans on North America’s Art. 9, page 12 of 14 Rick: Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of the Santa Barbara Channel, California, USA

Pacific Coast. Antiquity, 93e32(2019): 1–5. DOI: Vanishing Archaeological Record, 143–179. Santa https://doi.org/10.15184/aqy.2019.185 Barbara Museum of Natural History Contributions Erlandson, JM, Rick, TC, Ainis, A, Gill, KM, Jew, NP and in Anthropology 4. Santa Barbara: Santa Barbara Reeder-Myers, LA. 2020a. Shellfish, geophytes, Museum of Natural History. and sedentism on Early Holocene Santa Rosa Island, Graham, MH, Dayton, PK and Erlandson, JM. 2003. Alta California, USA. Journal of Island and Coastal Ice ages and ecological transitions on temperate Archaeology, in press. DOI: https://doi.org/10.1080 coasts. Trends in Ecology and Evolution, 18: 33–40. /15564894.2019.1579272 DOI: https://doi.org/10.1016/S0169-5347(02)00 Erlandson, JM, Rick, TC, Braje, TJ, Casperson, M, 006-X Culleton, B, Fulfrost, B, Garcia, T, Guthrie, Gusick, AE. 2012. Behavioral Adaptations and Mobil- DA, Jew, N, Kennett, DJ, Moss, M, L. Reeder, L, ity of Early Holocene Hunter-Gatherers, Santa Cruz Skinner, C, Watts, J and Willis, L. 2011. Paleo- Island, California. PhD Dissertation, University of coastal seafaring, maritime technologies, and coastal California, Santa Barbara. foraging on California’s Channel Islands. Science, Gusick, AE. 2013. The Early Holocene Occupation of 331: 1181–1185. DOI: https://doi.org/10.1126/ Santa Cruz Island. In: Jazwa, C and Perry, J (eds.), science.1201477 California’s Channel Islands: The Archaeology of Erlandson, JM and Rick, TC. 2002. Late Holocene cul- Human-Environment Interactions, 40–59. Salt Lake tural developments along the Santa Barbara Coast. City: University of Utah Press. In: Erlandson, JM and Jones, TL (eds.), Catalysts to Gusick, A and Erlandson JM. 2019. Paleocoastal Complexity: Late Holocene Societies of the California landscapes, marginality, and initial settle- Coast, 166–182. Los Angeles: Cotsen Institute of ment of California Islands. In: Gill, K, Fauvelle, Archaeology, University of California. DOI: https:// M and Erlandson, JM (eds.), An Archaeology of doi.org/10.2307/j.ctvhhhfdx.13 Abundance: Reevaluating the Marginality of Erlandson, JM, Rockwell, T, Braje, TJ, Joslin, T, California’s Islands, 59–97. Gainesville: University Leftwich, B, Ruiz, J, Stone, D and Victorino, K. Press of Florida. DOI: https://doi.org/10.5744/ 2020b. CA-SBA-56: an ‘Oak Grove’ and ‘Canalino’ site florida/9780813056166.003.0003 on the margins of the Goleta Lagoon, California. In: Higham, CFW. 2017. First farmers in mainland Southeast Glassow, MA (ed.) Goleta Slough Prehistory: Insights Asia. Journal of Indo-Pacific Archaeology, 41: 13–21. Gained from a Vanishing Archaeological Record, DOI: https://doi.org/10.7152/jipa.v41i0.15014 121–142. Santa Barbara Museum of Natural History Hildebrandt, WA, Ruby, A and Kaijankoski, P. 2020. Contributions in Anthropology 4. Santa Barbara: Middle Holocene resource intensification along Santa Barbara Museum of Natural History. the southern California Coast: a view from Goleta Gamble, LH. 2008. The Chumash World at Euro- Slough. In: Glassow, MA (ed.), Goleta Slough Pre- pean Contact: Power, Trade, and Feasting history: Insights Gained from a Vanishing Archaeo- among complex hunter-gatherers. Berkeley: logical Record, 97–119. Santa Barbara Museum of University of California Press. DOI: https://doi. Natural History Contributions in Anthropology 4. org/10.1525/9780520942684 Santa Barbara: Santa Barbara Museum of Natural Gill, KM and Hoppa, KM. 2016. Evidence for an Island History. Chumash geophyte-based subsistence economy on Jazwa, CS, Duffy CJ, Leonard, L and Kennett DJ. 2016. the Northern Channel Islands. Journal of California Hydrological modeling and prehistoric settlement and Great Basin Anthropology, 36: 51–71. on Santa Rosa Island, California, USA. Geoarchae- Giovas, CM. 2009. The shell game: analytic problems ology, 31: 101–120. DOI: https://doi.org/10.1002/ in archaeological mollusc quantification. Journal gea.21532 of Archaeological Science, 36: 1557–1564. DOI: Jazwa, CS, Kennett, DJ and Hansen, D. 2012. Late Holo- https://doi.org/10.1016/j.jas.2009.03.017 cene subsistence change and marine productiv- Glassow, MA. 1997. Middle Holocene cultural develop- ity on western Santa Rosa Island, Alta California. ments in the central Santa Barbara Channel Region. California Archaeology, 4: 69–98. DOI: https://doi. In: Erlandson, J and Glassow, M (eds.), The Archae- org/10.1179/cal.2012.4.1.69 ology of the California Coast During the Middle Jazwa, CS, Kennett, DJ and Winterhalder, B. 2013. Holocene, 73–90. Los Angeles: Cotsen Institute of The Ideal Free Distribution and settlement history Archaeology, University of California. of Old Ranch Canyon, Santa Rosa Island, California. Glassow, MA. (ed.). 2020a. Goleta Slough Prehistory: In: Jazwa, C and Perry, J (eds.), California’s Channel Insights Gained from a Vanishing Archaeological Islands: The Archaeology of Human-Environment Record. Santa Barbara Museum of Natural History Interactions, 75–96. Salt Lake City: University of Contributions in Anthropology 4. Santa Barbara: Utah Press. Santa Barbara Museum of Natural History. Jones, TL and Hadick, KC. 2016. Indigenous California. Glassow, MA. 2020b. Goleta Slough subsistence and In: Mooney, H and Zavaleta, E (eds.), Ecosystems settlement at 3500 B.C. In: Glassow, MA (ed.), of California, 169–184. Berkeley: University of Goleta Slough Prehistory: Insights Gained from a California Press. Rick: Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of Art. 9, page 13 of 14 the Santa Barbara Channel, California, USA

Jones, TL, Jones, DA, Hildebrandt, WR, Hadick, K and Edwards, RL, Friedrich, M, Grootes, PM, Mikkelsen, P. 2019. The Prehistory of Morro Bay: Guilderson, TP, Haflidason, H, Hajdas, I, Hatte, Central California’s Overlooked Estuary. University C, Heaton, TH, Hoffman, DL, Hogg, A, Hughen, of Utah Anthropological Papers 132. Salt Lake City: KA, Kaiser, KF, Kromer, B, Manning, SW, Niu, M, University of Utah Press. Reimer, RW, Richards, DA, Scott, EM, Southon, Kennett, DJ. 2005. The Island Chumash: Behavio- JR, Staff, RA, Turney, CSM and van der Plicht, J. ral Ecology of a Maritime Society. Berkeley: 2013. IntCal13 and Marine13 radiocarbon age cali- University of California Press. DOI: https://doi. bration curves 0–50,000 years cal BP. Radiocarbon, org/10.1525/9780520931435 55: 1869–1887. DOI: https://doi.org/10.2458/ Lebow, CG, Harro, DR, McKim, RL, Hodges, CM, azu_js_rc.55.16947 Munns, AM, Enright, EA and Haslouer, LG. The Reitz, E and Wing, E. 2008. Zooarchaeology, 2nd Edi- Sudden Flats Site: a Pleistocene/Holocene transition. Cambridge: Cambridge University Press. DOI: tion shell midden on Alta California’s Central Coast. https://doi.org/10.1017/CBO9780511841354 California Archaeology, 7: 265–294. DOI: https:// Rick, TC. 2009. 8,000 Years of human settlement and doi.org/10.1080/1947461X.2015.1108560 land use in Old Ranch Canyon, Santa Rosa Island, Lelièvre, M. 2017. Temporal changes in marine shellfish? California. In Damiani, C and Garcelon, D (eds.), Pro- A preliminary archaeological perspective from the ceedings of the seventh California Islands symposium, Northumberland Strait. Journal of the North Atlantic, 21–31. Arcata: Institute for Wildlife Studies. 10: 42–58. DOI: https://doi.org/10.3721/037.002. Rick, TC. 2019. Why so late? AMS radiocarbon evidence sp1006 of a Late Holocene appearance of shell fishhooks Masters, PM and Aiello, IW. 2007. Postglacial evolu- in Alta California. Journal of Island and Coastal tion of coastal environments. In: Jones, T and Klar, Archaeology, 14: 108–112. DOI: https://doi.org/10 K (eds.), California Prehistory: Colonization, Culture, .1080/15564894.2019.1579273 and Complexity, edited by, pp. 35–51. Walnut Creek: Rick, TC and Eliot, J. 2013. Pismo clam (Tivela stultorum) Altamira Press. harvest on Middle Holocene Santa Rosa Island, Minas, KR. 2017. Archaeological Testing at Water Canyon California. Journal of California and Great Basin in Support of the Santa Rosa Island campground Anthropology, 33: 61–71. septic system, Channel Islands National Park. CR Rick, TC, Kennett, DJ and Erlandson, JM. 2005. Prelimi- Project # 2004B, National Park Service. nary report on the archaeology and paleoecology Morris, RH, Abbott, DP and Haderlie, EC. 1980. Inter- of the Abalone Rocks Estuary, Santa Rosa Island, tidal Invertebrates of California. Stanford: Stanford California. In: Garcelon, D and Schwemm, C (eds.), University Press. Proceedings of the Sixth California Islands Sympo- Pollard, E. 2008. The maritime cultural landscape of sium, 55–63. National Park Service Technical Pub- Kilwa Kisiwani and its region, Tanzania, 11th to 15th lication CHIS-05-01. Arcata: Institute for Wildlife century AD. Journal of Anthropological Archaeol- Studies. ogy, 27: 265–280. DOI: https://doi.org/10.1016/j. Rick, TC, Robbins, JA and Ferguson, KM. 2006. Stable jaa.2008.07.001 isotopes from marine shells, ancient environments, Reeder-Myers, LA. 2014a. Multi-scalar foraging deci- and human subsistence on Middle Holocene Santa sions in the Santa Barbara Channel, southern Rosa Island, California, U.S.A. Journal of Island and California. Journal of Anthropological Archaeol- Coastal Archaeology, 1: 233–254. DOI: https://doi. ogy, 35: 202–219. DOI: https://doi.org/10.1016/j. org/10.1080/15564890600935480 jaa.2014.06.002 Smith, T and McNiven, IJ. 2019. Aboriginal marine sub- Reeder-Myers, LA. 2014b. 9,000 years of settle- sistence foraging flexibility in a dynamic estua- ment in the Carrington Point area of Santa Rosa rine environment: the late development of Tin Island, Alta California. California Archaeology, 6: Can Inlet (southeast Queensland) middens revis- 247–271. DOI: https://doi.org/10.1179/1947461X ited. Queensland Archaeological Research, 22: 14Z.00000000042 1–38. DOI: https://doi.org/10.25120/qar.22.2019 Reeder-Myers, LA, Erlandson, JM, Muhs, D and Rick, .3670 TC. 2015. Sea level, paleogeography, and archaeol- Stringer, CB, Finlayson, JC, Barton, RNE, ogy on California’s northern Channel Islands. Qua- Fernandez-Jalvo, Y, Cáceres I, Sabin, RC, ternary Research, 83: 263–272. DOI: https://doi. Rhodes, EJ, Currant, AP, Rodríguez-Vidal, J, org/10.1016/j.yqres.2015.01.002 Giles-Pacheco, F and Riquelme-Cantal, J. 2008. Reeder-Myers, LA, Rick, TC, Lowery, DL,Wah, J and Neanderthal exploitation of marine mammals in Henkes, G. 2016. Human ecology and coastal Gibraltar. Proceedings of the National Academy of foraging at Fishing Bay, Maryland, USA. Journal Sciences USA, 105: 14319–14324. DOI: https://doi. of Ethnobiology, 36: 595–616. DOI: https://doi. org/10.1073/pnas.0805474105 org/10.2993/0278-0771-36.3.595 Thakar, HB. 2011. Intensification of shellfish exploita- Reimer, PJ, Bard, E, Bayliss, A, Beck, JW, Blackwell, tion: evidence of species-specific deviation from PG, Bronk Ramsey, C, Buck, CE, Cheng, H, traditional expectations. Journal of Archaeological Art. 9, page 14 of 14 Rick: Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of the Santa Barbara Channel, California, USA

Science, 38: 2596–2605. DOI: https://doi. Voorhies, B. 2004. Coastal Collectors in the Holocene: The org/10.1016/j.jas.2011.05.008 Chantuto People of Southwest Mexico. Gainesville: Vellanoweth, RL and Erlandson, JM. 2004. Coastal University Press of Florida. paleogeography and human land use at Tecolote Wolff, CB, Rick, TC and Aland, A. 2007. Middle Holocene Canyon, southern California U.S.A. Geoarchaeol- subsistence and land use on Southeast Anchorage, ogy, 19: 141–165. DOI: https://doi.org/10.1002/ Santa Rosa Island, California. Journal of California gea.10111 and Great Basin Anthropology, 27: 44–56.

How to cite this article: Rick, TC. 2020. Early to Middle Holocene Estuarine Shellfish Collecting on the Islands and Mainland Coast of the Santa Barbara Channel, California, USA. Open Quaternary, 6: 9, pp. 1–14. DOI: https://doi.org/10.5334/oq.86

Submitted: 11 June 2020 Accepted: 26 July 2020 Published: 03 September 2020

Copyright: © 2020 The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC-BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. See http://creativecommons.org/licenses/by/4.0/.

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