In 1980, the National Oceanic and Atmospheric Administration (NOAA) designated Channel Islands National Marine Sanctuary (CINMS) located off the coast of Santa Barbara and Ventura counties in California. The sanctuary encompasses 1,470 square miles surrounding five of the Channel Islands: San Miguel, Santa Rosa, Santa Cruz, Anacapa, and Santa Barbara. The sanctuary's remote, isolated position at the confluence of two major ocean currents supports remarkable biodiversity and productivity. The mingling of cool, nutrient-rich waters from the north with warm currents from the south form a dynamic transition zone that is home to a myriad of sea life from microscopic plankton to blue whales. Many valuable commercial and recreational activities, such as fishing, shipping, and tourism, occur in the sanctuary. The sanctuary is a special place for sensitive habitats and living resources, shipwrecks, other maritime heritage artifacts, and living Chumash culture.
The purpose of a condition report is to use the best available science and most recent data to assess the status and trends of various parts of the sanctuary's ecosystem. The first condition report for Channel Islands was released in 2009; this report marks a second comprehensive update to describe the status and trends of sanctuary resources. The findings in the Channel Islands NMS 2016 Condition Report, Volume I document status and trends in water quality, habitat, living resources, and maritime archaeological resources from 2009–2016, unless otherwise noted. The report helps identify gaps in current monitoring efforts, as well as causal factors that may require monitoring and potential remediation through management actions in the coming years. The data discussed will not only enable sanctuary resource managers and stakeholders to acknowledge and have a shared perspective on prior changes in resource status, but will also inform management efforts to address challenges stemming from pressures, such as increasing coastal populations and climate change.
The findings in the 2016 condition report will provide critical support for identifying high priority sanctuary management actions, specifically helping to shape updates to the CINMS Management Plan. The management plan helps guide future work and resource allocation decisions at CINMS by describing strategies and activities designed to address priority issues and advance core sanctuary programs. The next update to the sanctuary management plan will build on the 2009 management plan, which contains a number of actions to address issues and concerns (NMSP 2009). The 2009 plan stresses an ecosystem-based approach to management, which requires consideration of ecological interrelationships not only within the sanctuary, but also within the larger context of the California Current ecosystem. The next management plan review process is projected to begin in late 2018. The process will involve significant public input, agency consultations, and environmental compliance work, and depending on the complexity of actions proposed, may take one to three years to complete.
The sanctuary is adjacent to metropolitan Los Angeles - one of the largest U.S. population centers - and is therefore impacted by a large range of human activities and pressures. Due to its offshore location, human activities in the Channel Islands face different driving pressures than inshore or mainland activities. Driving forces behind these pressures can aid in predicting the direction and extent of future pressures. The majority of driving forces (resulting factors that lead to pressures) are increasing, such as population, per capita income, Gross Domestic Product (GDP) of trading partners, vessel traffic, and visitor use to the Channel Islands. Additionally, gasoline prices have been stable and relatively low making access affordable. The direction of these drivers indicate that pressures will continue to increase within the sanctuary.
While coastal nutrient runoff rarely reaches sanctuary waters, some persistent pollutants have been detected in sanctuary sediments and mussel tissues, and may be accumulating over time. Pollutants can reach the sanctuary through periodic transport by local currents, by animals, or via sediment transport. Over time, oil production has declined in the region around the sanctuary and has been fairly stable since 2012. While oil spills are rare, in 2015, a broken land pipe at Refugio Beach spilled crude oil into coastal waters, which may have reached the sanctuary. Marine debris enters the sanctuary from both water- and land-based activities, and it is likely accumulating in the water column and benthic habitats. Consequences of marine debris include accidental lethal ingestion by organisms, animals becoming entangled, and/or toxic bioaccumulation up the food chain.
Fishing practices in the vicinity of the sanctuary have generally shifted over time from bottom trawls and nets to traps and hook and line, meaning overall gear interactions with seafloor habitats have been reduced; however, trap loss is an issue of concern. No-take and restricted-take marine zones established in the sanctuary in 2004 and 2007 have had measurable benefits to fished populations and habitats. Visitation to the sanctuary has increased since 2009 and in turn, pressures like anchoring damage, non-native species introductions, and vessel grounding risks are also increasing. Some of the busiest shipping lanes in the world pass through a portion of the sanctuary and produce concerning amounts of noise. Increased ambient noise levels can impair some marine mammals, fishes, and invertebrates that rely on acoustics for communication and locating prey. Both small and large vessels can strike and harm or kill large whales, and this remains an ongoing management challenge. Global climate change has affected water quality, urchins, deep-water corals, and other habitat-forming species, and it will be crucial to better understand how these changes may impact the sanctuary's living resources and habitats over time.
The physical and biological oceanographic characteristics of the CINMS region are unique. Two major currents meet at the east-west oriented northern Channel Islands, making it a transition zone where surface temperatures shift from warm in the east, to cool in the west. There is notable seasonal variation of surface temperatures, currents, nutrients, pH, and dissolved oxygen levels. These factors combine to support one of the most productive and biologically diverse marine ecosystems in the world. Marine researchers are also drawn to the CINMS region, and therefore many long-term datasets exist, including for water quality. Compared to coastal areas, the water quality of the sanctuary is good. A disruption to normal conditions occurred with a warm water event, unprecedented in size and duration that began in 2013 and lasted through much of 2016. During this event, the Southern California Bight experienced anomalously warm surface waters, reduced mixing and surface nutrients, and low productivity. Impacts reverberated throughout regional food webs, and how the system rebounds will be a topic of continued research. Such marine heat waves are believed to be related to climate change, and this potential correlation should also be tracked over time. Climate drivers are currently the most concerning aspect of water quality, as the 2016 status and trend has reduced to fair and worsening. In addition to ocean warming and marine heat waves, other impacts of climate change that are the focus of ongoing study include ocean acidification, reductions in dissolved oxygen, and the intensity, frequency, and duration of harmful algal blooms (HABs). HABs are increasing in frequency and extent along the U.S. West Coast. While typical in the CINMS region, some researchers believe the onset and severity of HABs may be influenced by ocean warming and/or anomalous spikes in sea surface temperature. Continued monitoring will produce the necessary temporal and spatial data to better discern the factors that influence HABs and describe their ecosystem impacts.
The sanctuary is comprised of a highly diverse patchwork of habitats ranging from intertidal rocky habitat and sandy beaches, inshore kelp forests, soft bottom habitats and rocky reefs, and deep-sea coral gardens. Sanctuary habitats are defined both by abiotic (e.g., sediment/bottom type, depth, rugosity) and biogenic (e.g., kelp, algae, mussels, deep-sea corals) features that contribute to overall habitat quality, structure, and function. While data on change in abiotic habitat is limited, recent monitoring data shows a decline in the health or abundance in many species that create biogenic habitat from their growth (e.g., corals) or activities (e.g., burrowing). For example, critical habitat creators such as giant kelp, mussels, deep-sea corals, and seagrass are all experiencing declines in health, condition, or abundance. These trends appear to be the norm beyond the sanctuary's boundaries as well, suggesting that impacts are wide-spread across the Southern California Bight. Conversely, trends are spatially variable with temperature, top-down ecological controls, pH, conservation measures, and changes in fishing pressure; this variability also influences habitat quality among islands. While information is limited, pollution impacts on habitat quality appear to vary by monitoring methodology. Contaminant concentrations in mussel tissue appear to be declining for most metals; however, infaunal surveys from deeper waters have found a change in community composition, which may be a result of the impacts of pollution. While habitat quality and pollution appear to be worsening by some metrics, experts agree these trends have not yet caused severe degradation of ecological integrity within the sanctuary. Future work should focus on understanding the ecological consequences of this potential habitat loss and forecasting the response of habitat to changing climate, emerging contaminants, and fishing activities.
The abundance and diversity of wildlife seen around the northern Channel Islands is remarkable compared to many parts of the world and was a main reason for its sanctuary designation. Although the 2016 status and trends are quite variable across the range of species in the sanctuary, overall, the data indicate that many of the sanctuary's living resources are showing relative stability or improvement since 2009. For example, most kelp forest and seafloor-associated fishes are stable or increasing, especially inside no-take zones. Additionally, the number of native species in sanctuary habitats, which is one measure of biodiversity, appears to be stable with no known recent local extinctions; however, the island-wide drastic declines in sea stars, a keystone species in rocky shore and shallow reef habitats, coupled with the establishment of a few non-indigenous species at some island monitoring sites, contributed to worsening trends in the status of nearshore communities and raises concerns about future impacts to ecological integrity and biodiversity. In the pelagic habitats, unusual abundances and distributions of both forage species, such as squid and sardine, and their predators, including sea lions, were likely driven by an unusual warm water event that began in 2013 and lasted until 2016. Abundance of forage species typically rebounds with the return of favorable oceanographic conditions, but time is needed to better understand if there are any lasting impacts from these recent anomalies. Continued monitoring of living resources in sanctuary habitats will be essential to determine whether key species and community assemblages will return to past patterns or if new patterns are emerging in response to changing climate and other human pressures.
Assessment of data gathered through Channel Islands National Maritime Sanctuary and Channel Islands National Park's annual Shipwreck Reconnaissance Monitoring Program indicates that since 2009, maritime archaeological resources reflect little or no unexpected disturbance or looting by divers; however, a 2011 damage assessment was recorded at the Winfield Scott shipwreck site which was believed to be caused by improper vessel anchoring. Damage to historic iron artifacts was recorded, but believed to be caused by a vessel's anchor tackle, not by divers' activities. The monitoring program has also contributed to new historic artifact discoveries, such as the Pelorus navigation instrument located at the Equator shipwreck site in 2016. Maritime archaeological resources will continue to go through various stages of degradation caused by natural forces, especially those resources located in shallow water and impacted by surge and swells. The diminished condition of an archaeological resource could reduce its historical, archaeological, scientific, or educational value, and is likely to affect its eligibility for listing to the National Register of Historic Places. There are no known maritime archaeological resources that pose environmental threats, although some threats may come from shipwrecks located beyond sanctuary boundaries. Since the location of the majority of deep-water wrecks is unknown, impacts to archaeological resources by offshore trawling is still unknown.