Banderas Bay Research Articles

Upper mesophotic reef fish assemblages at Bahía de Banderas, Mexico.

There is no information on the species associated with the mesophotic reefs of Banderas Bay, located in the central Mexican Pacific. This study analysed the reef fish assemblage from three depths (50, 60 and 70 m) in three sampling sites of the southern submarine canyon of the Bay: Los Arcos, Bajo de Emirio and Majahuitas. Several analyses were performed to test the hypothesis that there are important differences in fish abundance and species composition between sites and depths. Twenty-two species of bony fishes grouped in 14 families were recorded. PERMANOVA results showed that there were no significant differences in fish diversity parameters between sites, indicating a certain uniformity in their distribution. However, nine species were exclusive to one site and depth (five singleton species with only one individual recorded and four unique species recorded only once). On the other hand, there were significant differences between depths, mainly between 50 and 70 m. Diversity decreases with depth and species composition changes. SIMPER, Shade Plot and NMDS analysis show the most representative species at each depth, with at least half of the species (11) recorded only at 50 m and four species at the deeper levels (60 - 70 m). The observed assemblage includes several of the most caught species in the shallow water artisanal fishery, which is the most traditional and common type of fishery in the Bay. In addition, the Pomacanthuszonipectus (Cortés angelfish) is of particular interest, as it has a special protection status in the official Mexican standard (NOM-059-SEMARNAT, 2010) due to its use as an ornamental species in aquaria. We hypothesised that the mesophotic zone may serve as a refuge for these fishes, so we propose that the information obtained is an important basis for new research aimed at the sustainable management of fisheries in the area.

Large whale entanglements in Mexico, a 25‐year review from 1996 to 2021

AbstractLarge whale entanglements are considered a significant threat to populations on a global scale. In the Mexican Pacific and Baja California Peninsula (1996–2021) a total of 218 confirmed entangled whales, from which 99 (45.4%) whales were fully released (66 by the Mexican Whale Disentanglement Network, known as RABEN). Five whale species were reported in confirmed entanglements: humpback (Megaptera novaeangliae, n = 187), gray (Eschrichtius robustus, n = 19), sperm (Physeter macrocephalus, n = 5), Bryde's (Balaenoptera edeni, n = 4), and fin (Balaenoptera physalus, n = 3). Eight types of fishing gear were identified out of 209 different gear sets; gill nets were the most common (n = 101, 48.3%), followed by pots (n = 49, 23.4%). Entanglements were reported in sixteen locations, and Banderas Bay had the most entanglement reports (n = 81, 32.8%). Several entanglements were tracked across multiple locations (n = 7), involving two teams with the most successful releases (n = 5), proving the efficiency of the RABEN entanglement response network. This information can be used to better understand entanglement impacts on large whales in the North Pacific and particularly in Mexico, to work towards mitigation of a problem that affects both whales and fishermen.

Environmental drivers of persistent humpback whale Megaptera novaeangliae feeding events in a Mexican breeding area

Humpback whales Megaptera novaeangliae typically fast for several months in low-latitude breeding areas. Here we report on persistent feeding events during 5 wintering seasons between 2013 and 2020 in a known upwelling region of Banderas Bay of the mainland Mexico breeding area. In total, there were 76 unique feeding events documented (group size = 1 to ~100 individuals), involving 201 photo-identified whales, of which 18 were documented feeding in multiple years. The most prolific years of documented feeding in 2017 and 2018 (based on number of reports/individuals photo-identified feeding) followed the strongest marine heatwave ever recorded in the North Pacific. Whales documented feeding in Banderas Bay had significantly shorter mean sighting histories (2.3 yr) than a non-feeding sample (8.7 yr) and were reported to be of small size, suggesting they were predominantly younger whales. Most high-latitude recaptures of Banderas Bay feeding whales were in more northern North Pacific feeding grounds (50.8% were resighted in Russia, Alaska, and northern British Colombia, Canada). A binomial general linear model revealed a significant relationship between the probability of whales feeding in Banderas Bay and sea surface temperature (SST). Specifically, feeding consistently occurred in years of lower than average winter SST (<25°C), associated with La Niña years of the El Niño Southern Oscillation (ENSO). We conclude that feeding of humpback whales is now a predictable occurrence in the upwelling region of Banderas Bay in years that ENSO fluctuations lead to lower regional SST. The magnitude of several years of low-latitude feeding events reported here was likely influenced by climate change induced marine heatwaves that occurred during the study period.

Benthic infauna associated with a shallow-water hydrothermal system of Punta Mita (Mexico)

Abstract The shallow-water hydrothermal system of Punta Mita in Banderas Bay is located on the fault called Fisura de las Coronas off Punta Pantoque beach. In this area, three sites with hydrothermal vents were studied at a depth of 9 m. This study aimed to characterize the structure of the benthic infauna communities that coexist in this hydrothermal system; therefore, physicochemical parameters were measured and the organisms found in the sediment samples were identified up to the class taxonomic level. The highest temperatures (89°C) were recorded within the hydrothermal influence area, which was reflected in an inverse relationship with pH, conductivity and salinity. Sediment temperature profiles increased at greater depth. A total of 371 individuals were found and these were grouped into eight classes: Malacostraca, Maxillopoda, Gastropoda, Bivalvia, Scaphopoda, Polychaeta, Leptocardii and Stenolaemata. The Malacostraca class was the most abundant with 240 individuals, while the Scaphopoda was the lowest with 3. The organic matter contents in the sediments were higher in the areas adjacent to the hydrothermal activity. The high temperature of the hydrothermal discharges structures the benthic community since it was the factor that differed most significantly in the study sites, causing lower abundances in the area of hydrothermal influence compared with the more distant areas. Despite the above, it is concluded that the benthic community of the area with hydrothermal activity is part of the community adjacent to this influence, only in lower numbers.

Spatial Ecology of Humpback Whales (Megaptera novaeangliae, Cetacea-Balaenopteridae) from the Mexican Central Pacific1

The Northeast Pacific subpopulation of the humpback whale migrates every winter-spring to Mexican waters to breed; however, their use of habitat in the Mexican Pacific remains unknown. We investigated the spatial ecology of the humpback whale in the Mexican Central Pacific (MCP) and connections with other Mexican areas. Surveys to search for humpback whales were conducted in winter-spring 2010–2019. The number of individuals, type of group, and activities were recorded, and flukes were photographed to differentiate individuals observed at Mexican areas. A total of 15,384.4 km were travelled in MCP waters and 462 groups of humpback whales were sighted. The dominant group were single and pairs, observed mainly off Colima coast. The principal activity was traveling, and the least frequent activity was likely-feeding. A total of 420 individuals were photo-identified, and through their sighting history, it was possible to calculate that only 2.14% (1.67–12.5%) of them showed site fidelity; this indicates that the MCP is a transit zone to other reproductive areas. A photographic catalog of 798 individuals from Socorro Island was also analyzed to compare with the MCP catalog, but there were no photo-recaptures between two areas. The comparison with catalogs of 302 individuals from the Guerrero coast and 1,459 individuals from Banderas Bay resulted in interchange indices of 1.02E–06 and 2.93E–07, respectively. The MCP is part of the breeding ground of humpback whales, but it seems to be a transit area that does not offer optimum conditions for permanence and sustained habitat use, possibly due to regional anthropogenic activities.

Aeromagnetic anomalies and magnetic domains of the Jalisco Block, western Mexico

The Jalisco Block (JB) in western Mexico has been considered as a margin terrane being detached from the North American plate along the Tepic-Zacoalco rift and Colima graben. In this study, an aeromagnetic analysis of the JB and surrounding areas is performed applying a series of geophysical filters and VOXI inverse model. The JB is characterized by two aeromagnetic domains (AMD). AMD-Ia located throughout the south-central section that borders the continental margin is characterized by positive magnetic anomalies extending from the Armería river to Banderas Bay. The AMD-Ia corresponds to the Puerto Vallarta batholith emplaced in the late Cretaceous. The AMD-IIa in the northern section is marked by negative magnetic anomalies over volcanic and volcano-sedimentary rocks, extending to the southern Sierra Madre Occidental. We propose that JB tectonic boundaries correspond to the aeromagnetic AMD-Ia eastern limit and AMD-IIa northern limit. Estimated depths from the radially average power spectrum for deep magnetic sources in the AMD-Ia are in the range of 5.4 km, and for shallow sources from 0.8 to 1.2 km. For AMD-IIa depths are 10.45 km for deep sources and 0.13 km for shallow sources. Depths for deep sources from the Euler deconvolution for the AMD-Ia range from 3.3 to 4.5 km and from 3.5 to 4.9 km for the AMD-IIa. Shallow source depths in the AMD-Ia are 0.2–0.3 km and near surface for the AMD-IIa. The integrated analysis shows five aeromagnetic domains, two associated with the JB and three with the surrounding areas. The VOXI inverse model allows to estimate the dimensions and location of magnetic sources in the reduced to the pole and upward continuations.

Humpback whales in Banderas Bay, Mexico: relative abundance and temporal patterns between 2004 and 2017

Banderas Bay, Mexico is an important breeding and transit area for the North Pacific humpback whale (Megaptera novaeangliae) population. In this paper we estimated relative abundance (RA = number of whales/hours of navigation) as a proxy to assess population temporary patterns in the area. We analyzed data from 14 breeding seasons (2004-2017), collected between December and March each winter. A total of 8,013 whales were observed in 1,394.6 navigation hours. Average seasonal RA was 5.7 whales per hour with a maximum of 7.5 (2013) and a minimum of 4.0 (2016). Sea surface temperature (SST) averaged 25.1°C and remained within the range considered optimal for humpback whale reproduction areas. SST showed no significant correlation with RA (r = 0.183). Inter-seasonal RA values suggested an increase throughout the study period, although the increase was not statistically significant (R = 0.32; R2 = 0.10; t = 1.15, p > 0.05). Intra-seasonal analyses showed that RA in December and January were significantly higher (U = 150, p < 0.05) than in February and March; this pattern was consistent throughout the seasons of study. These results represent a shift in the intra-seasonal abundance peak relative to previous studies when most whales were observed between January and February. It is important to recognize changes in population parameters of humpback whales in breeding areas to improve management practices. This study also highlights the potential of opportunistic platforms, such as whale watching tour boats, as viable sources of quality information, particularly in contexts when funding is limited.

Humpback whales (Megaptera novaeangliae) in the surrounding waters of Isabel Island in western-central Mexico: unveiling a little-known wintering area

AbstractThe humpback whales which breed in the Mexican Pacific represent an important fraction (~38%) of the estimated population of the North Pacific. Despite the importance of Mexican waters for the reproductive habits of this species, little is known about the ecology of these whales, along the continental coast of Mexico. We analysed the temporal variation of abundance, group types, and inter- and intra-annual recapture rates in the waters adjacent to Isabel Island National Park as well as intra- and inter-seasonal movements with Banderas Bay breeding areas. Inter- and intra-annual recapture rates in Isabel Island National Park were low (1.8%); while 34% of 222 individuals photo-identified in Isabel Island National Park were also recaptured in Banderas Bay. Groups with calves were uncommon (9.5%), while pairs (33.5%) and competitive groups (29.5%) were more common. Intense singing activity was detected in the waters adjacent to Isabel Island. These waters seem to function as a reproductive corridor for the so-called ‘coastal stock’ of humpback whales in the waters adjacent to the continental coast of the Mexican Pacific. Therefore, mid- and long-term studies are needed to understand the dynamics of these displacements. Our findings suggest that Isabel Island National Park is an important area for the mating ecology of the humpback whales of the continental waters of the Mexican coast, and support the initiative to incorporate a Marine Protected Area within the Isabel Island National Park.

Quantifying the Effects of Diver Interactions on Manta Ray Behavior at Their Aggregation Sites

Manta rays (Mobula birostris, Mobula. cf. birostris, andMobula alfredi), the largest mobulid rays, are subjected to exploitation and overfishing in certain parts of the world. Tourism has been supported as a sustainable alternative for the conservation of the species, and a potential source of economic spillover to local populations. Nevertheless, the effects of tourism over these highly social animals remains unknown. Manta rays aggregate at three sites in Mexico: Oceanic manta rays (M. birostris)in The Revillagigedo Archipelago and Banderas Bay in the Pacific. Caribbean manta rays (M. cf. birostris) around Isla Contoy National Park in the Caribbean. We analyzed the behavior of manta rays using video data collected by local researchers and tourism operators to determine how diver behaviors and techniques (SCUBA and free diving) affect them. Diver activities were grouped into passive and active categories. We described 16 behaviors and grouped them into four behavioral states: Directional, erratic, attraction and evasion to divers. We modeled the sequence of behaviors exhibited by manta rays via first order Markov chains. Our models accounted for passive and active diver behavior when modeling the changes in manta behavior. Manta rays in Banderas Bay and Revillagigedo displayed a higher frequency of erratic behaviors than at Isla Contoy, while Banderas Bay manta rays transitioned to evasion behaviors more often. Manta rays responded similarly in both sites to active divers. At freediving sites, manta rays from Isla Contoy displayed evasion less frequently than at Banderas Bay. Changes in manta ray behavior were similar for both sites, but mantas in Banderas Bay transitioned to evasion more with active divers. The increased food availability for Isla Contoy manta rays could be the reason for the reduced response toward divers in this site. The existence of additional stressors such as both traffic in Banderas Bay could be causing the mantas in this site to respond more frequently to active divers. This study, the first of its kind in oceanic and Caribbean manta rays, highlights that regulations and the use of best practices are vital for achieving longer and less disturbing encounters for both manta rays and divers.

Aptitud turística de las playas certificadas de la Bahía de Banderas, México

An evaluation of the recreational suitability of the certified beaches in Banderas Bay, Mexico, was carried out based on biophysical indicators and perceived values. At the same time, the affinity between the beaches was analysed by common tourism‑adapted components. The results show that the indicatos mark two separate groups that share certain affinity with only three beaches substantially differing from the rest. This evaluation shows coincidences associated with the natural landscape and differences in the availability of infrastructure and services, as well as the level of cleanliness and general quality of hygiene. The present analysis may be used as a trustworthy guide to how to managed tourism activities on the coast, since the meth‑ odologies developed in this research may be extrapolated to all the beaches in Mexico.

Granulometric Analysis of Shallow Vents Sediments at Banderas Bay (Mexico)

Ocean hydrothermal activity is well known from deep-sea studies; however, few studies have been reported at shallow depth. A shallow submarine hydrothermal system at Punta Mita described in 2000 was studied to determine the grain size classification of the marine sediments of this hydrothermal system. Three sites with hydrothermal activity were included. Each one was divided into three areas: with hydrothermal activity, intermediate, and out of hydrothermal activity. In each area, two sediment cores were randomly collected by scuba diving (number of sediment cores = 18). All sediment samples were subjected to a previous treatment, to eliminate salts and organic matter. The grain sizes were sieved and then classified following the Udden–Wentworth scale. A principal coordinate analysis was performed to determine if there was any association of the statistical moments with the areas and sites of study. The textural composition of the sediments in the hydrothermal influence areas is sand, where the very fine sand is the dominant grain size, which was confirmed with the mean moment. The sediments are characteristic of the tidal areas, except for those sediments in the areas with hydrothermal activity.

First Record of Amphioxus Branchiostoma californiense (Amphioxiformes: Branchiostomatidae) Adjacent to a Shallow Submarine Hydrothermal System at Banderas Bay (Mexico)

Shallow submarine hydrothermal vent systems assume differentiated environmental conditions. Some specimens of Branchiostoma californiense were found in the sediments of the influence area of the shallow hydrothermal venting in Punta Mita. This is the only lancelet species registered for the Mexican Pacific. The meristic and morphometric characteristics of the organisms first collected in unconsolidated sediments of this shallow system were reviewed, in order to determine the species. We confirm that it is the same species. This represents the first record of it for both the Banderas bay and in the influence area of a shallow hydrothermal system.

Intensive feeding of humpback whales (Megaptera novaeangliae) in the breeding ground of Banderas Bay, Mexico

Banderas Bay, located in the Mexican Pacific, is a breeding/calving ground for the North Pacific stock of humpback whales (Megaptera novaeangliae) during the winter. While sporadic registers of humpback whales feeding on their mating grounds exist, this is the first occasion where feeding activity was observed intensively and extensively on a breeding ground. Between 19 December 2011 and 6 March 2012, 26 such occurrences were registered in Banderas Bay, along the mainland pacific coast. On five occasions, groups of 20 or more individuals were recorded feeding. They were feeding over and under the surface using lunging and gulping techniques. On several occasions humpbacks were observed feeding alongside Bryde´s whales (Balaenoptera edeni), Pantropical spotted dolphins (Stenella attenuata) and Bottlenose dolphins (Tursiops truncatus). Two different samples of fish at two different feeding sites were taken and the fish identifications showed these were Pacific anchovies (Cetengraulis mysticetus). Among the 26 sightings, nine different species of birds were registered feeding in the same area as the humpback whales. The number of whales feeding over an extended period of time in their breeding ground could be an indicator that there was not enough food in their feeding grounds, but the possibility that they might just be taking advantage of good food availability is also possible.

Seasonal variation in the abundance of marine plastic debris in Banderas Bay, Mexico

A floating plastic monitoring program was conducted for two years on a weekly basis in Banderas Bay, Mexico. A total of 94 samples were collected from May 2016 to April 2018 in the southern part of the bay. Half (57%) of them contained plastic debris; 79% of it being <5 mm in length. Polypropylene and Polyethylene were the most abundant polymers, accounting for 45% and 43% of the plastic pieces (pp), respectively. The highest abundance of plastic pieces was found in July 2016, with a maximum of 0.3 pp/m3 found in one sample. The amount of floating plastics was significantly higher in the hurricane season compared to the dry season (p < 0.001). This suggests that rainfall may play a significant role in the offload of plastics from land-based sources into the bay.

Helminth parasite communities of spotted rose snapper Lutjanus guttatus from the Mexican Pacific

Summary The helminth communities of L. guttatus from Mazatlan Bay (MB) and Banderas Bay (BB), on the Pacific coast of Mexico, were studied during two consecutive years. A total of 536 fish were collected and 19 parasite taxa registered (six digeneans, two cestodes, nine nematodes, and two monogeneans). Infection levels of common helminth species (Helicometrina nimia, Siphodera vinaledwardsii, Tetraphyllidea gen. sp., Pseudoterranova sp., Ancyrocephalidae gen. sp. and Microcotyloides incisa) as well as the infracommunity indices varied significantly between MB and BB, and among dry and rainy seasons; however, no clear seasonal patterns were observed. Pseudoterranova larvae appeared frequently in MB, possibly because of the presence of the California sea lion in this locality. Similarity analysis did not show a clear separation of parasite species composition between both localities, which suggest that fish samples came from a single population of L. guttatus.

Modeling the Effect of a Submarine Canyon on Eddy Generation in Banderas Bay, México

ABSTRACT Pantoja, D.A.; Marinone, S.G., and Filonov, A., 2017. Modeling the effect of a submarine canyon on eddy generation in Banderas Bay, Mexico. Banderas Bay is located at the tip of Cabo Corrientes, a coastal promontory near the entrance of the Gulf of California. In this area, the intensification and recirculation of the Mexican Coastal Current (MCC) interact with Banderas Bay and, more specifically, a submarine canyon within the bay, in a manner that generates eddies. This eddy formation was explored using the Regional Ocean Modeling System (ROMS) numerical model in a series of idealized experiments consisting of a northward coastal current simulating the MCC. Banderas Bay is prone to generate eddies due to a headland and the very steep topography of the canyon. When the intensity of the currents at the entrance of the bay reaches 0.4 m s−1, the circulation exhibits detachments and then eddies. The eddies have azimuthal speeds of 0.1 to 0.3 m s−1 and diameters that are constrained by the bay/canyon...

The impact of vessel crowding on the probability of tourists returning to whale watching in Banderas Bay, Mexico

This article examines the influence of vessel crowding on the probability of tourists returning for whale watching at Banderas Bay in Mexico. We estimate a conditional probability model of the intention to return, which includes vessel crowding and other factors such as income and conservation attitudes as explanatory variables. We use a representative survey of 410 whale watching tourists. Our empirical results show that perceived crowding and reported crowding negatively affect the probability of tourists returning for a whale watching trip, while variables such as conservation attitude, specifically subjective norm, have positive impacts on such probability. Results show that most of the surveyed tourists would return if the number of boats around the whales were about two. These results suggest that well designed coastal management policies should include appropriate regulations on vessel crowding not only to protect the whales but also to increase the probability of tourists returning to the site. Proposed regulations on crowding might include evaluation of the actual norm and maintenance of permits as a regulation strategy, a code of conduct for all vessels and a zoning area.

Evidence of sexual reproduction in the hermatypic corals Pocillopora damicornis, Porites panamensis, and Pavona gigantea in Banderas Bay, Mexican Pacific

The reproductive capacity of coral communities in the Mexican Pacific is still poorly documented. One of the most abundant coral communities in this region is found in Banderas Bay, yet the reproductive patterns of the coral species have not been analyzed. In order to document the annual reproductive cycle of the three most common species of corals in the bay, samples of Pocillopora damicornis, Porites panamensis, and Pavona gigantea were collected monthly from Redonda Island from December 2001 to November 2002. Colony fragments were processed by histological techniques and analyzed under a microscope. The three species showed the presence of gametes, which was associated with an increase in sea surface temperature. Gametogenesis was first observed in P. damicornis, classified as hermaphrodite. In P. panamensis, reproductive cells were observed in May 2002, and embryos and planulae in September 2002; this species was classified as gonochoric, showing internal fertilization and a distinct reproductive behavior compared with that reported for other areas of the eastern tropical Pacific. In P. gigantea, gametogenesis started later and occurred over a short period of time; this species was classified as gonochoric and no mature gametes were evident. All three species showed reproductive potential during the summer, confirming the reproductive capacity documented for these species in adjoining areas of the Mexican Pacific. The intensity and duration of the reproductive cycle in Banderas Bay are likely regulated by periodic events like El Niño and microscale climate oscillations that modulate temperature and light patterns in the area.

Hyperiid Amphipods (Peracarida) from Banderas Bay, Mexican Tropical Pacific

Hyperiid Amphipods (Peracarida) from Banderas Bay, Mexican Tropical Pacific

Proliferaciones algales 2000-2001 en Bahía de Banderas, México según el sensor SeaWiFS

Algal blooms for the period of 2000 and 2001 at Banderas Bay, México, were analyzed from SeaWiFS-ocean-color-sensor derived information. These events were related with the maximum chlorophyll week anomalies (ASi; a proxy variable constructed for the analysis of chlorophyll temporal variation in the bay). The winter-spring blooms were multispecific, while the summer-fall blooms were monospecific. Two proposals are made: (1) Winter-spring blooms are strongly related with mesoescale processes, due to their apparent temporal synchrony with the high chlorophyll levels in the coastal region from Sinaloa to Jalisco states; (2) Cochlodinium polykrikoides (Margalef 1961) blooms during the summer-fall periods could be induced by local conditions and the influence of previous events on the ecosystem.