Effects of the 1997–1998 El Niño on the cnidarian community of a high turbidity coral reef system (northern Bahia,Brazil)

We are reporting on the results of a 4-year study that allowed for the analysis of the effects of the 1997–1998 El Niño Southern Oscillation (ENSO) event on the cnidarian community of the naturally high-turbidity reefs of northern Bahia, Brazil. Cnidarian densities were significantly different between pre- and post-ENSO years, with significant consequent changes in community composition. BIOENV analysis identified variations in turbidity, mean temperature variance, and cloud cover as the factors best explaining changes in the community. We suggest that the 1997–1998 ENSO event, the most intense on record, had a differential effect on the cnidarian community. Highest mortalities were suffered by minute hydroid colonies, partial mortality by octocorals and actiniarians, while large hydroid colonies and scleractinians were the least affected. Such an ability to survive under the stressful environmental regime imposed by this ENSO event is attributed to the presence of morphological pre-adaptations (e.g., size of colony polyps, abundance of certain nematocyst types) and the inherent phenotypic plasticity that results from long-term exposure to naturally stressful conditions.     

LIFE ON THE EDGE: STRESS SURVIVAL ADAPTATIONS IN SOUTHERN LIMIT MACROCYSTIS PYRIFERA POPULATIONS

In spite of subtropical temperatures often occurring at the Macrocystis pyrifera distributional southern limit in the Northern Hemisphere in Baja California, Mexico, the population has been successful at surviving and recovering from disturbance. To explore the physiological characteristics of southern limit M. pyrifera , microscopic and macroscopic phases of southern limit plants were tested for stress tolerance and compared to northern plant responses in three experiments. In spore development experiments, under constant temperature and nitrate stress treatments, spores from the southern-limit population survived higher temperatures, had greater survivorship, and were able to complete their life cycle at higher temperatures and lower nitrate concentrations than northern population spores. During stress-recovery treatments, where all microscopic stages were tested for recovery after stress shock exposure (temperature, nitrate and light stress), 96% of all haploid treatments showed some regrowth during recovery; haploid survival was not significantly affected by spore population origin, light, or nitrate. However, only 26% of diploid treatments showed regrowth and diploid survival was significantly affected by spore population origin; only the southern limit spores recovered after stress treatment exposure. In juvenile transplant experiments, under all conditions, juvenile plants originating from the southern-limit had higher tissue nitrogen content, greater frond addition rates, and higher photosynthetic efficiency than northern plants, particularly at higher temperatures. The physiological differences observed for the southern limit plants versus those from the north contributes to our understanding of how the southern limit plants can survive in an environment that might otherwise be considered extreme for the species.     

CHANGES IN THE RELATIVE ABUNDANCE AND DISTRIBUTION OF GRAY WHALES (ESCHRICHTIUS ROBUSTUS) IN MAGDALENA BAY, MEXICO DURING AN EL NIÑO EVENT

The oceanographic changes during the El Niño and La Niña of 1998–1999 have provided an opportunity to document the effects of these events on the migratory patterns of gray whales ( Eschrichtius robustus ). Magdalena Bay is located at the southernmost point of the gray whale's annual breeding migration along the Baja California Peninsula in Mexico. Standardized surveys were conducted for three consecutive seasons (1997–1999) in Magdalena Bay, enabling an assessment of the changes in the relative abundance of gray whales with altered temperature. The average temperature of the bay in 1998 was 4.2°C higher than in 1997 and 5.8°C higher than in 1999. The number of whale sightings during that time period was inversely related to temperature, with nearly 15 times greater relative abundance observed in 1999 than in 1998. It is hypochesized that the decreasing temperatures associated with the La Niña event of 1999 may have induced more whales to travel farther south along their migration route. Alternative hypotheses are also expiored. Comparisons of the three years are discussed with consideration of the importance of environmental conditions versus area fidelity as determining factors in the location of gray whale calving and breeding activities.     

Short-term impact of disturbance on genetic diversity and structure of Indonesian populations of the butterfly Drupadia theda in East Kalimantan

We investigated the short‐term impact of disturbance on genetic diversity and structure of the tropical butterfly Drupadia theda Felder (Lepidoptera: Lycaenidae). Populations were sampled from five landscapes in East Kalimantan (Borneo, Indonesia) which were differentially disturbed by selective logging and the 1997/1998 El Niño Southern Oscillation (ENSO)‐induced drought and fires. Sampling occurred before (in 1997) and after the forest fires (in 1998, 1999, 2000, and 2004). Drupadia theda populations underwent serious population size reductions following the 1997/1998 ENSO event. For a total of 208 individuals, we sequenced a 509‐bp segment of mtDNA containing the control region plus the 5’ end of the 12S rDNA gene. Haplotype diversity in D. theda populations ranged from 0.468 to 0.953. Just after the 1997/1998 ENSO event, number of recorded individuals and genetic diversity were very low in D. theda populations sampled in the two severely burned areas and in a small pristine forest fragment that was surrounded by burned forest and thereby affected by drought. Interestingly, higher levels of genetic diversity were observed in logged forest compared to proximate pristine forest. After 1998, the genetic composition within the three ENSO‐disturbed areas diverged. In the twice‐burned forest, the genetic diversity in 1999 already approached pre‐fire levels, while it remained nearly unchanged in proximate once‐burned forest. Our data suggest that the 1997/1998 ENSO‐induced drought and fires caused massive reductions in the genetic diversity of D. theda and that population recoveries were linked to their geographical position relative to patches of unburned forest (and thus to source populations).     

Interannual distribution of Pacific hake Merluccius productus larvae in the southern part of the California Current

The interannual distribution of early life stages of Pacific hake Merluccius productus , within the southern part of the California Current (32–23° N) from 1951 to 2001, was examined to describe the relationship between spawning habitat and environmental conditions. Mean annual abundance was affected by different factors along the west coast of the Baja California Peninsula. In the northern areas (Ensenada and Punta Baja), reduced abundance of larvae coincided with the El Niño and a North Pacific Ocean climatic regime shift, but in the southern areas (San Ignacio to Bahía Magdalena), the drastic reductions suggested a fishery effect for large adults of the coastal migratory population, starting in 1966. Two spawning stocks, coastal and dwarf, were evident in comparisons of latitudinal differences in occurrence of early stages and differences in temperature preferences that seemed to break at Punta Eugenia.     

Rapid growth and early flowering in an invasive plant,purple loosestrife (<Emphasis Type="Italic">Lythrum salicaria</Emphasis> L.) during an El Niño spring

Phenological shifts may play a role in the success of invasive species, especially in association with climatic variability. We studied the response of a North American population of the invasive plant, Lythrum salicaria L., to changes in local climate associated with the El Niño/Southern Oscillation Event (ENSO) of 1997–1998. For L. salicaria plants at two wetland sites near North Bay, Ontario, Canada, we made weekly observations of flowering phenology and monthly measurements of aboveground biomass during the 1997 and 1998 growing seasons (April–October). Reproductive output was measured as cumulative length and biomass of inflorescences at the end of the growing season. Temperature and precipitation during the 1997 growing season were typical for the region and provided good baseline data for comparison to the full effects of the ENSO event in 1998, which increased spring temperatures and reduced precipitation in the study area. In response to these conditions, populations of L. salicaria began to flower 14 days earlier (Julian day = 181 ± 10) in 1998 than in 1997 (Julian day = 195 ± 12), and accumulated more aboveground biomass early in the growing season (P < 0.05). However, by the end of the growing season, there were no significant differences between years in aboveground biomass or total inflorescence lengths, and senescence of plants occurred at similar times for both growing seasons. Advances in spring phenology during ENSO events offer several potential advantages to L. salicaria, and could have a significant impact on biological control programs initiated for this species in North America.     

Long Term Variability in the Structure of Kelp Communities in Northern Chile and the 1997–98 ENSO

This is the first study on the south eastern Pacific coast of South America which details long term, interannual variability in the structure of subtidal rocky-bottom kelp-dominated communities before, during, and after the El Niño Southern Oscillation (ENSO) event of 1997–1998 in northern Chile (23^°S). The temporal patterns of the main components of these ecosystems, which included Macrocystis integrifolia, Lessonia trabeculata, echinoids and asteroids, were evaluated seasonally between 1996 and 2004. M. integrifolia demonstrated high interannual variability in temporal patterns of abundance. The 1997–1998 ENSO did not significantly modify the temporal patterns of Macrocystis, although local extinction of M. integrifolia beds occurred during negative thermal anomalies in 1999–2000 (La Niña event), facilitating the establishment of urchin dominated “barren grounds”. The abundance of Lessonia trabeculata showed little temporal variability, and this species dominated the deeper regions of the kelp assemblage (8–13 m depth). The structure of the kelp communities in the study area is regulated by a trophic cascade which modulates alternation between kelp dominated areas and sea urchin barrens. In this context, frequent and intense upwelling of cold water high in nutrients favors the establishment and persistence of kelp assemblages. During ENSO, coastal upwellings can mitigate superficial warming of coastal water and increase the nutrient concentration in the water column. Superficial warming during the 1997–1998 ENSO induced spawning by different species of echinoderms, which resulted in major recruitment of these species during 1999. Top-down events, such as the decrease in densities of the asteroids after the 1997–1998 ENSO event, favored increases in densities of benthic grazers, which caused significant decreases in abundance of M. integrifolia. The re-establishment of the adult fraction of the carnivore (starfish) guild coincided with a decrease in the density of sea urchins and thus re-establishment of the kelp. In the temperate south eastern Pacific, oceanographic events, which act on different spatial-temporal scales, trigger trophic cascades that act at local levels, producing interannual variability in the structure of kelp communities. On the other hand, considering the high macroinvertebrate diversity associated with kelp assemblages, the transitions between kelp-dominated areas and sea urchin barrens do not appear to significantly affect the biodiversity of these assemblages of benthic invertebrates.     

Carryover effects associated with winter location affect fitness, social status, and population dynamics in a long-distance migrant

We used observations of individually marked female black brant geese (Branta bernicla nigricans; brant) at three wintering lagoons on the Pacific coast of Baja California-Laguna San Ignacio (LSI), Laguna Ojo de Liebre (LOL), and Bahía San Quintín (BSQ)-and the Tutakoke River breeding colony in Alaska to assess hypotheses about carryover effects on breeding and distribution of individuals among wintering areas. We estimated transition probabilities from wintering locations to breeding and nonbreeding by using multistratum robust-design capture-mark-recapture models. We also examined the effect of breeding on migration to wintering areas to assess the hypothesis that individuals in family groups occupied higher-quality wintering locations. We used 4,538 unique female brant in our analysis of the relationship between winter location and breeding probability. All competitive models of breeding probability contained additive effects of wintering location and the 1997-1998 El Ni?o-Southern Oscillation (ENSO) event on probability of breeding. Probability of breeding in non-ENSO years was [Formula: see text], [Formula: see text], and [Formula: see text] for females wintering at BSQ, LOL, and LSI, respectively. After the 1997-1998 ENSO event, breeding probability was between 2% (BSQ) and 38% (LOL) lower than in other years. Individuals that bred had the highest probability of migrating the next fall to the wintering area producing the highest probability of breeding.     

Reproductive biology of the swell shark Cephaloscyllium ventriosum (Carcharhiniformes: Scyliorhinidae)

The Cephaloscyllium ventriosum shark is present in the artisanal fisheries of elasmobranchs on the western coast of Baja California Sur, Mexico. The main characteristics of the sexual maturation of this species based on individuals captured from off north-west Mexico in 2013–2016 are described. The size at maturity of this species was determined for the first time (total length 82 cm for females and 76 cm for males). Most females had one egg case per one uterus, and two per one uterus was an isolated event of low incidence. From the histological analysis of females, it was possible to show sperm storage in the oviducal gland. Fully developed sperm in immature organisms were identified in the testes. The main indicator of the maturity stage of males and their mating activity is the clasper. The present study provides evidence for a reliable estimation of the sexual maturity of these organisms, demonstrating the need for the combination of macroscopic and microscopic methods.     

Fluctuations of Vanessa cardui butterfly abundance with El Niño and Pacific Decadal Oscillation climatic variables

Annual 4th of July Butterfly Count data spanning more than 20 years are examined to explore Vanessa cardui (Painted Lady) population fluctuations with ENSO (El Niño) and Pacific Decadal Oscillation (PDO) indices. California, Colorado and Nebraska censuses exhibit a strong positive correlation with the strong El Niño events of 1982–1983 and 1997–1998 and the weaker event of 1991–1992. Regression analysis shows the population fluctuations are strongly coupled to climate variations on both short (El Niño) and longer (Pacific Decadal Oscillation) time scales. Recognizing the sensitivity to these time scales is important for predicting longer‐term global climate change effects.     

Possible Phytoplasma Disease in Papaya (Carica papaya L.) from Baja California Sur: Diagnosis by Scanning Electron Microscopy

The symptoms of possible phytoplasma infection in introduced and local varieties of papaya were first noted in the Mexican state of Baja California Sur (BCS) during field surveys in 2002–2003. Phytoplasma structures were observed using scanning electron microscopy (SEM) in phloem sieve elements in diseased papaya plants, but not in healthy plants. They were rounded structures 400–1600 nm in diameter. This is the first report of the possible association of phytoplasmas with diseased papaya plants in BCS. The use of SEM for the primary detection of disease aetiology is discussed.     

Sea Surface Temperature Influence on Terrestrial Gross Primary Production along the Southern California Current

Some land and ocean processes are related through connections (and synoptic-scale teleconnections) to the atmosphere. Synoptic-scale atmospheric (El Niño/Southern Oscillation [ENSO], Pacific Decadal Oscillation [PDO], and North Atlantic Oscillation [NAO]) decadal cycles are known to influence the global terrestrial carbon cycle. Potentially, smaller scale land-ocean connections influenced by coastal upwelling (changes in sea surface temperature) may be important for local-to-regional water-limited ecosystems where plants may benefit from air moisture transported from the ocean to terrestrial ecosystems. Here we use satellite-derived observations to test potential connections between changes in sea surface temperature (SST) in regions with strong coastal upwelling and terrestrial gross primary production (GPP) across the Baja California Peninsula. This region is characterized by an arid/semiarid climate along the southern California Current. We found that SST was correlated with the fraction of photosynthetic active radiation (fPAR; as a proxy for GPP) with lags ranging from 0 to 5 months. In contrast ENSO was not as strongly related with fPAR as SST in these coastal ecosystems. Our results show the importance of local-scale changes in SST during upwelling events, to explain the variability in GPP in coastal, water-limited ecosystems. The response of GPP to SST was spatially-dependent: colder SST in the northern areas increased GPP (likely by influencing fog formation), while warmer SST at the southern areas was associated to higher GPP (as SST is in phase with precipitation patterns). Interannual trends in fPAR are also spatially variable along the Baja California Peninsula with increasing secular trends in subtropical regions, decreasing trends in the most arid region, and no trend in the semi-arid regions. These findings suggest that studies and ecosystem process based models should consider the lateral influence of local-scale ocean processes that could influence coastal ecosystem productivity.     

Breeding biology and conservation of the Black-vented Shearwater Puffinus opisthomelas

The Black-vented Shearwater Puffinus opisthomelas is endemic to the Pacific coast of Baja California, Mexico. We studied the breeding biology of this species at Natividad Island in 1997 and 1998. The colony at Natividad Island covers approximately 2.5 km² and we estimated there to be 114 455 (± 27 520 95% CI) burrows in the colony. In 1997 burrow occupancy was 66.9%, providing a population estimate of 76 570 (± 18 411 95% CI) breeding pairs, representing about 95% of the world's population of this species. In 1997 the peak in egg laying occurred in early March and hatching began on 7 May. The incubation period averaged 51 days (± 6 sd) and chick rearing averaged 69 days (± 3 sd). In 1998 burrow occupancy was lower (19.6%) and nest initiation was later (peak egg laying in mid-April), perhaps a result of El Niño conditions that prevailed in the Eastern Pacific at that time. We calculated that the development of the town and roads on Natividad Island have destroyed over 15% (26 532 burrows) of the breeding habitat on the island.     

Changes in rain forest butterfly diversity following major ENSO-induced fires in Borneo

Aims Throughout South‐East Asia, droughts associated with ENSO (El Niño Southern Oscillation) events have resulted in large‐scale fires affecting millions of hectares of rain forest. However, the long‐term impacts of these fires on the rain forest faunas are only poorly understood. Our aim was to study the recovery of rain forest butterfly assemblages following the 1997–98 ENSO event, which resulted in the largest‐scale fires in the recorded history of the region. Location A 420‐km² area in the Balikpapan‐Samarinda region of East Kalimantan, Indonesian Borneo. Methods Four landscapes were assessed after the 1997–98 ENSO event, including one landscape that was assessed prior to the event. Comparisons of species richness, species composition and guild abundance were made among landscapes and years. The relative importance of environment, geographical distance between sampling sites, and time between sampling years was quantified during the succession phase using a variance partitioning technique. Results The fires dramatically altered the butterfly community and resulted in a major decline in observed species richness within the landscape surveyed prior to the ENSO event. Following fires in 1998, butterfly assemblages in all landscapes were dominated by large‐winged generalist species. During 1999 and 2000, assemblages became increasingly dominated by smaller specialist species. Species endemic to Borneo that were present before fires were absent in 2000, despite intensive sampling over enhanced spatial and environmental scales. Community similarity was significantly dependent upon local environmental variables, geographical distance between sampling sites, and time between sampling years. Together, these explained over 52% of the observed variation in samples. Conclusions The importance of geographical distance between sampling sites indicates that recovery was dependent upon colonization from proximate habitats. Despite an apparent trend of return to pre‐ENSO community structure, low species richness throughout the survey area indicates that full recovery had not taken place by 2000.     

Ecological aspects of Sargassum muticum (Fucales,Phaeophyta) in Baja California,Mexico: reproductive phenology and epiphytes

The reproductive phenology and epiphytic macroalgae of Sargassum muticum were studied through an annual cycle (September 1987 to November 1988) at two sites on the northwestern coast of Baja California, Mexico, which were subjected to different degrees of wave exposure. Sargassum muticum is a brown alga of Japanese origin, now considered a permanent member of the marine flora of Baja California. A similar reproductive development was observed at both sites, with a maximum percentage of reproductive plants from May to July (spring–summer) and minimum from December to March (winter). Reproductive plants were found throughout the year. A total of 48 species of epiphytes were identified and seasonal variation in their diversity was observed. The greatest diversity was found at the more protected site.     

Vegetative propagation and spore-based recruitment in the carrageenophyte Chondracanthus chamissoi (Gigartinales, Rhodophyta) in northern Chile

In the present study we compared vegetative and spore‐based propagation for Chondracanthus chamissoi (C. Agardh) Kützing. Monthly field observations were made over a 1‐year period at Puerto Aldea, Tongoy Bay, Chile. Data were collected both outside and within a bed of C. chamissoi. Vegetative propagation was assessed via attachment of drifting fronds to shell‐encrusted concrete blocks at both sites. Germination of spores was recorded on the same shell substrates. Substrate re‐adhesion varied seasonally between sectors. Highest averages occurred within the algal bed between January 1997 and March 1997. The number of sporelings showed two peaks of maximal recruitment in spring and summer months (January‐March 1997 and September 1997‐January 1998). Spore‐based propagation is an important mechanism of seasonal regeneration of biomass in the C. chamissoi bed; however, re‐attachment of fronds may have been important in maintaining production of the bed during the period of maximum biomass accumulation.     

Studies of morphological and molecular phylogenetic divergence in spiders (Araneae: Homalonychus) from the American southwest, including divergence along the Baja California Peninsula

Comparative phylogenetic and phylogeographic analyses have revealed a pervasive midpeninsular divergence in the mitochondrial genealogies of numerous vertebrate taxa distributed on the Baja California Peninsula. In this study, we extend the investigation of regional vicariance in Baja California to an arthropod taxon by examining patterns of phylogenetic and morphological divergence in the spider genus Homalonychus (Araneae, Homalonychidae). We analyzed data from two mtDNA genes (16S rRNA and NADH dehydrogenase subunit (1) and a nuclear gene (28S rRNA) using maximum parsimony and Bayesian phylogenetic analyses, and also conducted geometric morphometric analyses employing landmark data on male and female genitalia. Genes and morphology both reveal a deep split across the Colorado River and Gulf of California, separating Homalonychus selenopoides on the east side of river from its congener Homalonychus theologus on the west side of the river, including the Baja California Peninsula. Along the north-south axis of the Baja Peninsula, an apparently more recent midpeninsular phylogenetic break is evident within H. theologus in the mitochondrial genome and in female genitalia. However, there is no measurable divergence between northern and southern populations in either nuclear DNA or male genitalia. We suggest that this discordance between datasets reflects either a difference in rates of evolution between male versus female systems, or that male-based nuclear gene flow is obscuring a phylogenetic split that is fixed in the female-based systems. Our findings provide additional support for a midpeninsular Baja divergence event, although the timing and geological evidence for such an event remain elusive.     

Larval dynamics of the sand crab, Emerita analoga, off the central Oregon coast during a strong El Nino period

Populations of the sand crab, Emerita analoga, are well establishedon the California coast. However, populations in Oregon occursporadically and appear to be restocked by larvae drifting northfrom California. Due to increased northward transport in winterduring El Niño events, we would expect that larval recruitmentto northern populations should be higher during these periods.This hypothesis was tested by comparing larval abundances betweennon-El Niño and El Niño years, 1997 and 1998,respectively. In 1997, larval abundances and seasonality weresimilar to historical data from 1969–71. First zoeal (Z1)stage larvae were present during these summers, but in low numbers,indicating that E.analoga spawned off the coast of Oregon. In1998, strong larval recruitment from the south occurred, demonstratedby a large number of fifth zoeal stage (Z5) larvae collectedoff Oregon in April and May. The large numbers of Z1 found insummer 1998 indicate that the Z5, which arrived from Californiaearlier that spring, successfully recruited to adulthood andreproduced. These data indicate that Oregon E.analoga populationsare probably dependent on larvae travelling from Californiain the Davidson Current. It follows that this species couldbe used as an indicator of coastal current fluctuations suchas those seen during El Niño events.     

Biogeography and endemism of ants (Hymenoptera: Formicidae) in Baja California, Mexico: afirst overview

Abstract Aims Ants (Hymenoptera: Formicidae) of the Baja California peninsula are poorly known, with information based largely on scattered museum and literature records. We provide the first comprehensive account of ant species occurring on the peninsula, we examine distribution patterns, and we assess the ‘peninsular effect’ which predicts that species richness declines from the base to the tip of a peninsula. Location Peninsula of Baja California, Mexico. Methods Data collection involved examining, identifying and recording label data from c. 2350 series of ants. These records provide a provisional, if incomplete, species list. We applied the incidence‐based estimator, Chao‐2, to our data base of specimen records to estimate the total number of ant species on the peninsula. We assessed endemism by comparing our peninsular species list to those from adjacent states. The peninsular effect was tested by comparing genus and species level richness between the two states of Baja California, and across five latitudinal blocks. Results We document 170 native ant species in thirty‐three genera, plus six non‐native species, in Baja California. It seems likely that additional species remain to be discovered: the Chao‐2 estimator of species richness, at 206.0 species, is about 20% higher than our observed species richness. About 30% of the species and 20% of the genera are restricted within Baja California to the relatively mesic California Floristic Province of north‐western Baja California. Nearly all of these species also occur in California. Forty‐seven species (27.6%) are peninsula endemics. Using our entire data set, the peninsular effect appears to be strong, with about twice as many species in the northern state of Baja California than are recorded from the southern state of Baja California Sur; the ratio of genera is 33 to 24. However, this effect becomes weak at the species level and absent at the genus level when minimizing habitat effects by omitting species restricted to the California Floristic Province. At a finer scale, across latitudinal blocks of about 1.9°, the number of species declines towards central portions of the peninsula and then increases in the Cape Region. Nine ant species display strongly disjunct distributions, and these occur in two general patterns: peninsula disjuncts and peninsula–mainland disjuncts. Main conclusions The Baja California peninsula supports a diverse and distinctive ant fauna, with the proportion of endemic species similar to that displayed by plants. Patterns of species and genus richness across the five latitudinal blocks provide poor support for the peninsular effect. Moreover, habitat diversity, especially that related to topographic relief, appears to be the most important factor affecting the gradient of ant species richness in Baja California. Additional collections are needed to develop a more complete species list and to determine the boundaries and status of many species. Nevertheless, the present data base provides a useful starting point for understanding the evolution of ant assemblages in Baja California and for comparison with peninsular patterns in other taxa.     

ABUNDANCE OF BLUE AND HUMPBACK WHALES IN THE EASTERN NORTH PACIFIC ESTIMATED BY CAPTURE-RECAPTURE AND LINE-TRANSECT METHODS

We estimated humpback and blue whale abundance from 1991 to 1997 off the west coast of the U. S. and Mexico comparing capture-recapture models based on photographically identified animals and line-transect methods from ship-based surveys. During photo-identification research we obtained 4,212 identifications of 824 humpback whales and 2,403 identifications of 908 blue whales primarily through non-systematic small-boat surveys along the coast of California, Oregon, and Washington. Line-transect surveys from NOAA ships in 1991, 1993, and 1996 covered approximately 39,000 km along the coast of Baja California, California, Oregon, and Washington out to 555 km from shore. The nearshore and clumped distribution of humpback whales allowed photographic identification from small boats to cost-effectively sample a substantial portion of the population, but made it difficult to obtain effective samples in the line-transect surveys covering broad areas. The humpback capture-recapture estimates indicated humpback whale abundance increased over the six years (from 569 to 837). The broader more offshore distribution of blue whales made it harder to obtain a representative sample of identification photographs, but was well suited to the line-transect estimates. The line-transect estimates, after correction for missed animals, indicated approximately 3,000 blue whales (CV = 0.14). Capture-recapture estimates of blue whales were lower than this: approximately 2,000 when using photographs obtained from the line-transect surveys as one of the samples. Comparison of the results from the two methods provides validation, as well as insight into potential biases associated with each method.