Southern California's megaflood event of ca. 1605 AD linked to large-scale atmospheric forcing

A distinct, 1- to 2-cm-thick flood deposit found in Santa Barbara Basin with a varve-date of 1605 AD ± 5 years testifies to an intensity of precipitation that remains unmatched for later periods when historical or instrumental records can be compared against the varve record. The 1605 AD ± 5 event correlates well with Enzel's (1992) finding of a Silver Lake playa perennial lake at the terminus of the Mojave River (carbon-14-dated 1560 AD ± 90 years), in relative proximity to the rainfall catchment area draining into Santa Barbara Basin. According to Enzel, such a persistent flooding of the Silver Lake playa occurred only once during the last 3,500 years and required a sequence of floods, each comparable in magnitude to the largest floods in the modern record. To gain confidence in dating of the 1605 AD ± 5 event, we compare Southern California's sedimentary evidence against historical reports and multi-proxy time-series that indicate unusual climatic events or are sensitive to changes in large-scale atmospheric circulation patterns. The emerging pattern supports previous suggestions that the first decade of the 17th century was marked by a rapid cooling of the Northern Hemisphere, with some indications for global coverage. A burst of volcanism and the occurrence of El Nino seem to have contributed to the severity of the events. The synopsis of the 1605 AD ± 5 years flood deposit in Santa Barbara Basin, the substantial freshwater body at Silver Lake playa, and much additional paleoclimatic, global evidence testifies for an equatorward shift of global wind patterns as the world experienced an interval of rapid, intense, and widespread cooling.

Climate forcing of Pacific herring recruitment and growth in southern British Columbia

Over the last 50 years, much of the variability in ocean climate and herring recruitment has occurred at two dominant periods centered around 5 and 16 years. Herring growth has also exhibited a dominant 5- and 18-year periodicity. A recent analysis of a number of relevant time series suggests that interannual variations in oceanic conditions off the west coast of Vancouver Island affect survival of herring and their principal predator, Pacific hake, which also exhibits a marked 16-year oscillation in abundance. Thus the dynamics of the herring stock are modulated by a combination of climate and predator forcing. Much of the interannual variation in herring growth is centered around the 5-year (moderate ENSO period) and 16-year (strong ENSO period) ocean climate oscillations and the 16-year recruitment oscillation.

Climate forcing by changing solar radiation

By how much does changing radiation from the Sun influence Earth's climate compared with other natural and anthropogenic processes? Answering this question is necessary for making policy regarding anthropogenic global change, which must be detected against natural climate variability. Current knowledge of the amplitudes and time scales of solar radiative output variability available from contemporary solar monitoring and historical reconstructions can help specify climate forcing by changing radiation over multiple time scales.

PICES-GLOBEC International Program on Climate Change and Carrying Capacity: Report of the 1999 MONITOR and REX Workshops, and the 2000 MODEL Workshop on Lower Trophic Level Modelling

Table of Contents [pdf, 0.11 Mb] Executive Summary [pdf, 0.07 Mb] MODEL Task Team Workshop Report Final Report of the International Workshop to Develop a Prototype Lower Trophic Level Ecosystem Model for Comparison of Different Marine Ecosystems in the North Pacific [pdf, 11.64 Mb] Report of the 1999 MONITOR Task Team Workshop [pdf, 0.32 Mb] Report of the 1999 REX Task Team Workshop Herring and Euphausiid population dynamics Douglas E. Hay and Bruce McCarter Spatial, temporal and life-stage variation in herring diets in British Columbia [pdf, 0.10 Mb] Augustus J. Paul and J. M. Paul Over winter changes in herring from Prince William Sound, Alaska [pdf, 0.08 Mb] N. G. Chupisheva Qualitative texture characteristic of herring (Clupea pallasi pallasi) pre-larvae developed from the natural and artificial spawning-grounds in Severnaya Bay (Peter the Great Bay) [pdf, 0.07 Mb] Gordon A. McFarlane, Richard J. Beamish and Jake SchweigertPacific herring: Common factors have opposite impacts in adjacent ecosystems [pdf, 0.15 Mb] Tokimasa Kobayashi, Keizou Yabuki, Masayoshi Sasaki and Jun-Ichi Kodama Long-term fluctuation of the catch of Pacific herring in Northern Japan [pdf, 0.39 Mb] Jacqueline M. O’Connell Holocene fish remains from Saanich Inlet, British Columbia, Canada [pdf, 0.40 Mb] Elsa R. Ivshina and Irina Y. Bragina On relationship between crustacean zooplankton (Euphausiidae and Copepods) and Sakhalin-Hokkaido herring (Tatar Strait, Sea of Japan) [pdf, 0.14 Mb] Stein Kaartvbeedt Fish predation on krill and krill antipredator behaviour [pdf, 0.08 Mb] Nikolai I. Naumenko Euphausiids and western Bering Sea herring feeding [pdf, 0.07 Mb] David M. Checkley, Jr. Interactions Between Fish and Euphausiids and Potential Relations to Climate and Recruitment [pdf, 0.08 Mb] Vladimir I. Radchenko and Elena P. Dulepova Shall we expect the Korf-Karaginsky herring migrations into the offshore western Bering Sea? [pdf, 0.75 Mb] Young Shil Kang Euphausiids in the Korean waters and its relationship with major fish resources [pdf, 0.29 Mb] William T. Peterson, Leah Feinberg and Julie Keister Ecological Zonation of euphausiids off central Oregon [pdf, 0.11 Mb] Scott M. Rumsey Environmentally forced variability in larval development and stage-structure: Implications for the recruitment of Euphausia pacifica (Hansen) in the Southern California Bight [pdf, 3.26 Mb] Scott M. Rumsey Inverse modelling of developmental parameters in Euphausia pacifica: The relative importance of spawning history and environmental forcing to larval stage-frequency distributions [pdf, 98.79 Mb] Michio J. Kishi, Hitoshi Motono & Kohji Asahi An ecosystem model with zooplankton vertical migration focused on Oyashio region [pdf, 33.32 Mb] PICES-GLOBEC Implementation Panel on Climate Change and Carrying Capacity Program Executive Committee and Task Team List [pdf, 0.05 Mb] (Document pdf contains 142 pages)

Report of the PICES-STA Workshop on Monitoring Subarctic North Pacific Variability

The PICES Science Board and the Science and Technology Agency of Japan held a Workshop on Monitoring Subarctic North Pacific Vaiability,October 22-23,1994, in Nemuro,Hokkaido,Japan,in conjunction with the PICES Third Annual Meeting. The Workshop was not intended to discuss process studies or to review the science of the subaractic Pacific,but rather to focus on the longterm monitoring programs required for assessment of the physical and ecological responses to long-term forcing,both natural and man-made. (PDF contains 90 pages)

Marine ecosystems of the North Pacific

Key Messages [pdf, 2.5 Mb] Climate Information Gaps Ocean Productivity Information gaps Living Marine Resources Information gaps Climate [pdf, 1.8 Mb] Productivity [pdf, 5.2 Mb] Nutrients Phytoplankton Zooplankton Living Resources [pdf, 10 Mb] Subarctic coastal systems Central oceanic gyres Temperate coastal and oceanic systems Marine mammals The Human Population [pdf, 5 Mb] Contaminants and Habitat Modifications Aquaculture Knowledge Gaps Glossary Ocean and Climate Changes [pdf, 4.1Mb] Highlights Introduction Atmospheric Indices Change in 1998/99 Comparison of Atmospheric Indices Authorship Yellow Sea / East China Sea [pdf, 2.3 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Benthos Fish and invertebrates Marine birds and mammals Issues Critical factors causing change Authorship Japan/East Sea [pdf, 3.3 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Critical factors causing change Issues Authorship Okhotsk Sea [pdf, 1.7 Mb] Background Status and Trends Climate Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Issues Critical factors causing change Authorship Oyashio / Kuroshio [pdf, 4.5 Mb] Highlights Background Status and Trends Hydrography Plankton Fish and Invertebrates Marine Birds and Mammals Issues Authorship Western Subarctic Gyre [pdf, 4.5 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Issues Authorship Bering Sea [pdf, 2.2 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Critical Factors Causing Change Issues Authorship Gulf of Alaska [pdf, 2.6 Mb] Highlights Background Status and trends Hydrography Chemistry Plankton Fish and Invertebrates Marine birds and mammals Critical factors causing change Issues Authorship California Current [pdf, 2.7 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Critical Factors Causing Change Issues Authorship Gulf of California [pdf, 1.7 Mb] Highlights Background Status and Trends Hydrography Chemistry Plankton Fisheries Marine Birds and Mammals Critical Factors Causing Change Issues Authorship Transition Zone [pdf, 2.5 Mb] Background Status and Trends Hydrography Chemistry Plankton Fish and Invertebrates Marine Birds and Mammals Issues Authorship Tuna [pdf, 1.5 Mb] Highlights Background Pacific bluefin tuna Albacore tuna Status and trends Ecosystem model and climate forcing Authorship Pacific halibut [pdf, 1.1 Mb] Background The Fishery Climate Influences Authorship Pacific salmon [Updated, pdf, 0.4 Mb] Background Status and Trends Washington, Oregon, and California British Columbia Southeast Alaska Central Alaska Western Alaska Russia Japan Authorship References [pdf, 0.5 Mb]

Some considerations on coastal processes relevant to sea level rise

The effects of potential sea level rise on the shoreline and shore environment have been briefly examined by considering the interactions between sea level rise and relevant coastal processes. These interactions have been reviewed beginning with a discussion of the need to reanalyze previous estimates of eustatic sea level rise and compaction effects in water level measurement. This is followed by considerations on sea level effects on coastal and estuarine tidal ranges, storm surge and water level response, and interaction with natural and constructed shoreline features. The desirability to reevaluate the well known Bruun Rule for estimating shoreline recession has been noted. The mechanics of ground and surface water intrusion with reference to sea level rise are then reviewed. This is followed by sedimentary processes in the estuaries including wetland response. Finally comments are included on some probable effects of sea level rise on coastal ecosystems. These interactions are complex and lead to shoreline evolution (under a sea level rise) which is highly site-specific. Models which determine shoreline change on the basis of inundation of terrestrial topography without considering relevant coastal processes are likely to lead to erroneous shoreline scenarios, particularly where the shoreline is composed of erodible sedimentary material. With some exceptions, present day knowledge of shoreline response to hydrodynamic forcing is inadequate for long-term quantitative predictions. A series of interrelated basic and applied research issues must be addressed in the coming decades to determine shoreline response to sea level change with an acceptable degree of confidence. (PDF contains 189 pages.)

2002-03 Florida Keys National Marine Sanctuary science report: An ecosystem report card after five years of marine zoning

Executive Summary: Circulation and Exchange of Florida Bay and South Florida Coastal Waters The coastal ecosystem of South Florida is comprised of distinct marine environments. Circulation of surface waters and exchange processes, which respond to both local and regional forcings, interconnect different coastal environments. In addition, re-circulating current systems within the South Florida coastal ecosystem such as the Tortugas Gyre contribute to retention of locally spawned larvae. Variability in salinity, chlorophyll, and light transmittance occurs on a wide range of temporal and spatial scales, in response to both natural forcing, such as seasonal precipitation and evaporation and interannual “El Niño” climate signals, and anthropogenic forcing, such as water management practices in south Florida. The full time series of surface property maps are posted at www.aoml.noaa.gov/sfp. Regional surface circulation patterns, shown by satellite-tracked surface drifters, respond to large-scale forcing such as wind variability and sea level slopes. Recent patterns include slow flow from near the mouth of the Shark River to the Lower Keys, rapid flow from the Tortugas to the shelf of the Carolinas, and flow from the Tortugas around the Tortugas Gyre and out of the Florida Straits. The Southwest Florida Shelf and the Atlantic side of the Florida Keys coastal zone are directly connected by passages between the islands of the Middle and Lower Keys. Movement of water between these regions depends on a combination of local wind-forced currents and gravitydriven transports through the passages, produced by cross-Key sea level differences on time scales of several days to weeks, which arise because of differences in physical characteristics (shape, orientation, and depth) of the shelf on either side of the Keys. A southeastward mean flow transports water from western Florida Bay, which undergoes large variations in water quality, to the reef tract. Adequate sampling of oceanographic events requires both the capability of near real-time recognition of these events, and the flexibility to rapidly stage targeted field sampling. Capacity to respond to events is increasing, as demonstrated by investigations of the 2002 “blackwater” event and a 2003 entrainment of Mississippi River water to the Tortugas. (PDF contains 364 pages.)

Net phytoplankton and zooplankton in the New York Bight, January 1976 to February 1978, with comments on the effects of wind, Gulf Stream eddies, and slope water intrusions

Results are given of monthly net phytoplankton and zooplankton sampling from a 10 m depth in shelf, slope, and Gulf Stream eddy water along a transect running southeastward from Ambrose Light, New York, in 1976, 1977, and early 1978. Plankton abundance and temperature at 10 m and sea surface salinity at each station are listed. The effects of atmospheric forcing and Gulf Stream eddies on plankton distribution and abundance arc discussed. The frequency of Gulf Stream eddy passage through the New York Bight corresponded with the frequency of tropical-subtropical net phytoplankton in the samples. Gulf Stream eddies injected tropical-subtropical zooplankton onto the shelf and removed shelfwater and its entrained zooplankton. Wind-induced offshore Ekman transport corresponded generally with the unusual timing of two net phytoplankton maxima. Midsummer net phytoplankton maxima were recorded following the passage of Hurricane Belle (August 1976) and a cold front (July 1977). Tropical-subtropical zooplankton which had been injected onto the outer shelf by Gulf Stream eddies were moved to the inner shelf by a wind-induced current moving up the Hudson Shelf Valley. (PDF file contains 47 pages.)

Trace Metal Sensors for Coastal Monitoring, Seaside, California, April 11-13, 2005: workshop proceedings

The Alliance for Coastal Technologies (ACT) Workshop on Trace Metal Sensors for Coastal Monitoring was convened April 11-13, 2005 at the Embassy Suites in Seaside, California with partnership from Moss Landing Marine Laboratories (MLML) and the Monterey Bay Aquarium Research Institute (MBARI). Trace metals play many important roles in marine ecosystems. Due to their extreme toxicity, the effects of copper, cadmium and certain organo-metallinc compounds (such as tributyltin and methylmercury) have received much attention. Lately, the sublethal effects of metals on phytoplankton biochemistry, and in some cases the expression of neurotoxins (Domoic acid), have been shown to be important environmental forcing functions determining the composition and gene expression in some groups. More recently the role of iron in controlling phytoplankton growth has led to an understanding of trace metal limitation in coastal systems. Although metals play an important role at many different levels, few technologies exist to provide rapid assessment of metal concentrations or metal speciation in the coastal zone where metal-induced toxicity or potential stimulation of harmful algal blooms, can have major economic impacts. This workshop focused on the state of on-site and in situ trace element detection technologies, in terms of what is currently working well and what is needed to effectively inform coastal zone managers, as well as guide adaptive scientific sampling of the coastal zone. Specifically the goals of this workshop were to: 1) summarize current regional requirements and future targets for metal monitoring in freshwater, estuarine and coastal environments; 2) evaluate the current status of metal sensors and possibilities for leveraging emerging technologies for expanding detection limits and target elements; and 3) help identify critical steps needed for and limits to operational deployment of metal sensors as part of routine water quality monitoring efforts. Following a series of breakout group discussions and overview talks on metal monitoring regulatory issues, analytical techniques and market requirements, workshop participants made several recommendations for steps needed to foster development of in situ metal monitoring capacities: 1. Increase scientific and public awareness of metals of environmental and biological concern and their impacts in aquatic environments. Inform scientific and public communities regarding actual levels of trace metals in natural and perturbed systems. 2. Identify multiple use applications (e.g., industrial waste steam and drinking water quality monitoring) to support investments in metal sensor development. (pdf contains 27 pages)

A 30-Year History of Tide and Current Measurements in Elkhorn Slough, California

Elkhorn Slough was first exposed to direct tidal forcing from the waters of Monterey Bay with the construction of Moss Landing Harbor in 1946. Elkhorn Slough is located mid-way between Santa Cruz and Monterey close to the head of Monterey Submarine Canyon. It follows a 10 km circuitous path inland from its entrance at Moss Landing Harbor. Today, Elkhorn Slough is a habitat and sanctuary for a wide variety of marine mammals, fish, and seabirds. The Slough also serves as a sink and pathway for various nutrients and pollutants. These attributes are directly or indirectly affected by its circulation and physical properties. Currents, tides and physical properties of Elkhorn Slough have been observed on an irregular basis since 1970. Based on these observations, the physical characteristics of Elkhorn Slough are examined and summarized. Elkhorn Slough is an ebb-dominated estuary and, as a result, the rise and fall of the tides is asymmetric. The fact that lower low water always follows higher high water and the tidal asymmetry produces ebb currents that are stronger than flooding currents. The presence of extensive mud flats and Salicornia marsh contribute to tidal distortion. Tidal distortion also produces several shallow water constituents including the M3, M4, and M6 overtides and the 2MK3 and MK3 compound tides. Tidal elevations and currents are approximately in quadrature; thus, the tides in Elkhorn Slough have some of the characters of a standing wave system. The temperature and salinity of lower Elkhorn Slough waters reflect, to a large extent, the influence of Monterey Bay waters, whereas the temperature and salinity of the waters of the upper Slough (>5 km from the mouth) are more sensitive to local processes. During the summer, temperature and salinity are higher in the upper slough due to local heating and evaporation. Maximum tidal currents in Elkhorn Slough have increased from approximately 75 to 120 cm/s over the past 30 years. This increase in current speed is primarily due to the change in tidal prism which has increased from approximately 2.5 to 6.2 x 106 m3 between 1956 and 1993. The increase in tidal prism is the result of both 3 rapid man-made changes to the Slough, and the continuing process of tidal erosion. Because of the increase in the tidal prism, the currents in Elkhorn Slough exhibit positive feedback, a process with uncertain consequences. [PDF contains 55 pages]

The effect of long term exploitation by the gill net fishery on the multispecies fish stocks in Kainji Lake, Nigeria, 1969-1997

The findings are presented of an assessment made of the gillnet fishery in Kainji Lake, Nigeria from 1969 to the present, on the basis of data sets from commercial and experimental gillnet fishing, with the purpose to detect trends in some key fishery monitoring indicators. During this period, there has been an increase in the number of small meshed nets in the fishery resulting in a shift in the mode to lower mesh sizes; consequently, the average mesh size declined gradually in the fishery. This trend is found to be directly correlated with the decline in the CPUE and mean weight of the fish species. It is argued that the observed trend in CPUE and mean weight is forcing the fishermen to switch effort to gears such as traps which have very small meshes and can indescriminately take all sizes of the fish. It is shown that the catch composition by weight of Citharinus citharus, Lates niloticus and tilapias declined in the gillnet fishery in the late 70's and early 80's. Recent data, from 1994 to 1996, however indicates that C. citharus is recovering, but with declining mean weight. This suggests that the exploitation pattern is shifting to the smaller fish through the use of small meshed nets. In general, however, there has not been drastic changes in species bio-diversity in the Lake as a result of predatory effect and ecosystem overfishing as has happened in other great African Lakes. The species composition since lake formation continued to be dominated by fewer that 20 species. The potential yield for the lake has been estimated to be 32,166 tonnes (excluding clupeids) and the required optimum fishing effort to be 1,814 fishing canoes. In view of the relative stability of the species diversity in the lake and the current fish production level, it is proposed here that this MSY be adopted for all species. This would be achieved with the current effort level in the lake assuming that the efficiency of the fishermen and their gears do not improve. It should be reviewed after 10 or more years of catch and effort data collection. (PDF contains 65 pages)

Hypoxic and low pH water in the nearshore marine environments of Monterey Bay, California: characterizing a decade of oxygen and pH, and drivers of variability.

A decade-long time series recorded in southern Monterey Bay, California demonstrates that the shallow, near-shore environment (17 m depth) is regularly inundated with pulses of cold, hypoxic and low pH water. During these episodes, oxygen can drop to biologically threatening levels, and pH levels were lower than expected. Weekly water chemistry monitoring revealed that the saturation state of aragonite (the more soluble form of calcium carbonate) was often below saturation and had a moderate positive relationship with pH, however, analytical and human error could be high. Pulses of hypoxia and low pH water with the greatest intensity arise at the onset of the spring upwelling season, and fluctuations are strongly semidurnal (tidal) and diurnal. Arrival of cold, hypoxic water on the inner shelf typically occurs 3 days after the arrival of a strong upwelling event and appears to be driven by upwelling modulated by internal tidal fluctuations. I found no relationship between the timing of low-oxygen events and the diel solar cycle nor with terrestrial nutrient input. These observations are consistent with advection of hypoxic water from the deep, offshore environment where water masses experience a general decline of temperature, oxygen and pH with depth, and inconsistent with biochemical forcing. Comparisons with concurrent temperature and oxygen time series taken ~20 km away at the head of the Monterey Canyon show similar patterns but even more intense hypoxic events due to stronger semidiurnal forcing there. Analysis of the durations of exposure to low oxygen levels establishes a framework for assessing the ecological relevance of these events. Increasing oceanic hypoxia and acidification of both surface and deep waters may increase the number, intensity, duration and spatial extent of future intrusions along the Pacific coast. Evaluation of the resiliency of nearshore ecosystems such as kelp forests, rocky reefs and sandy habitats, will require consideration of these events.

Stage-specific vertical distribution of Alaska plaice (Pleuronectes quadrituberculatus) eggs in the eastern Bering Sea

The stage-specific distribution of Alaska plaice (Pleuronectes quadrituberculatus) eggs in the southeastern Bering Sea was examined with collections made in mid-May in 2002, 2003, 2005, and 2006. Eggs in the early stages of development were found primarily offshore of the 40-m isobath. Eggs in the middle and late stages of development were found inshore and offshore of the 40-m isobath. There was some evidence that early-stage eggs occur deeper in the water column than late-stage eggs, although year-to-year variability in that trend was observed. Most eggs were in the later stages of development; therefore the majority of spawning is estimated to have occurred a few weeks before collection—probably April—and may be highly synchronized among local spawning areas. Results indicate that sampling with continuous underway fish egg collectors(CUFES) should be supplemented with sampling of the entire water column to ensure adequate samples of all egg stages of Alaska plaice. Data presented offer new information on the stage-dependent horizontal and vertical distribution of Alaska plaice eggs in the Bering Sea and provide further evidence that the early life history stages of this species are vulnerable to near-surface variations in hydrographical conditions and climate forcing.

Growth and survival of sockeye salmon (Oncorhynchus nerka) from Karluk Lake and River, Alaska, in relation to climatic and oceanic regimes and indices, 1922–2000

We examined whether the relationship between climate and salmon production was linked through the effect of climate on the growth of sockeye salmon (Oncorhynchus nerka) at sea. Smolt length and juvenile, immature, and maturing growth rates were estimated from increments on scales of adult sockeye salmon that returned to the Karluk River and Lake system on Kodiak Island, Alaska, over 77 years, 1924–2000. Survival was higher during the warm climate regimes and lower during the cool regime. Growth was not correlated with survival, as estimated from the residuals of the Ricker stock-recruitment model. Juvenile growth was correlated with an atmospheric forcing index and immature growth was correlated with the amount of coastal precipitation, but the magnitude of winter and spring coastal downwelling in the Gulf of Alaska and the Pacific Northwest atmospheric patterns that influence the directional bifurcation of the Pacific Current were not related to the growth of Karluk sockeye salmon. However, indices of sea surface temperature, coastal precipitation, and atmospheric circulation in the eastern North Pacific were correlated with the survival of Karluk sockeye salmon. Winter and spring precipitation and atmospheric circulation are possible processes linking survival to climate variation in Karluk sockeye salmon.