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

2021 ◽  
pp. 1-9
Author(s):  
Fabiola L. Zavala-Alarcón ◽  
Astrid Frisch-Jordán ◽  
Verónica Carolina Rosas-Espinoza ◽  
Hiram Rosales-Nanduca
Keyword(s):  
National Park ◽  
Marine Protected Area ◽  
Humpback Whales ◽  
Mexican Pacific ◽  
The North ◽  
Continental Coast ◽  
Singing Activity ◽  
Wintering Area ◽  
The North Pacific

Abstract The 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.

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

10.5597/00251 ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 27-33
Author(s):  
Astrid Frisch-Jordán ◽  
Nicola Ransome ◽  
Oscar Aranda-Mena ◽  
Fernando Romo-Sirvent
Keyword(s):  
Feeding Activity ◽  
Bottlenose Dolphins ◽  
Extended Period ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Breeding Ground ◽  
Mexican Pacific ◽  
The North ◽  
Stenella Attenuata ◽  
The North Pacific

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.

scholarly journals Response Characteristics of Chinese Pine (Pinus tabulaeformis Carr.) Radial Growth to Climate and Drought Variability Reconstruction in Western Liaoning, Northeast China

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 752
Author(s):  
Liu ◽  
Bao ◽  
Bao
Keyword(s):  
Northeast China ◽  
Radial Growth ◽  
Pinus Tabulaeformis ◽  
Western Liaoning ◽  
Chinese Pine ◽  
The Past ◽  
The North ◽  
Pinus Tabulaeformis Carr ◽  
The North Pacific

Chinese pine (Pinus tabulaeformis Carr.) plays an important role in maintaining ecosystem health and stability in western Liaoning Province and the southern Horqin sand land, Northeast China, with benefits including sand fixation and soil erosion. In the context of climate change, developing a better understanding of the relationship between climate factors and growth rates of this species will be extremely valuable in guiding management activities and meeting regional conservation objectives. Here, the results based on two groups of tree-ring samples show that the radial growth of Chinese pine is controlled primarily by water conditions. The longer chronology had the highest correlation coefficient with the January–September mean self-calibrating Palmer Drought Severity Index (scPDSI); therefore, drought variability was reconstructed for the period 1859–2014. Statistical analysis showed that our model explained 41.9% of the variance in radial growth during the 1951–2014 calibration period. Extreme dry and wet events, defined as the criteria of one standard deviation less or greater than the mean value, accounted for 19.9% and 18.6% of the 156-year climate record, respectively. During the past century, the regional hydroclimate experienced significant long-term fluctuations. The dry periods occurred from the early-1900s–1930s and 1980s–2000s, and the wet periods occurred from the 1940s–1970s. The drought reconstruction was consistent with the decreasing trend of the East Asian summer monsoon since the late 1970s. The reconstructed temporal patterns in hydroclimate in western Liaoning were closely related to the large-scale climate drivers in the North Pacific and the tropical equatorial Pacific. The teleconnections were confirmed by spatial correlations between the reconstructed sequence and sea surface temperature (SST) in the North Pacific, as well as the correlations with the Pacific Decadal Oscillation (PDO) and El Niño Southern Oscillation (ENSO) indices. Aerosols played an important role in affecting drought variations over the past several decades. Moisture stress caused by global warming and interdecadal changes in the PDO will have long-term effects on the growth of pines in the study area in the future.

Increasing anthropogenic nitrogen in the North Pacific Ocean

Science ◽  
2014 ◽  
Vol 346 (6213) ◽  
pp. 1102-1106 ◽  
Author(s):  
Il-Nam Kim ◽  
Kitack Lee ◽  
Nicolas Gruber ◽  
David M. Karl ◽  
John L. Bullister ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Limited Region ◽  
The North ◽  
Term Change ◽  
Rate Of Increase ◽  
Anthropogenic Nitrogen ◽  
The North Pacific

The recent increase in anthropogenic emissions of reactive nitrogen from northeastern Asia and the subsequent enhanced deposition over the extensive regions of the North Pacific Ocean (NPO) have led to a detectable increase in the nitrate (N) concentration of the upper ocean. The rate of increase of excess N relative to phosphate (P) was found to be highest (∼0.24 micromoles per kilogram per year) in the vicinity of the Asian source continent, with rates decreasing eastward across the NPO, consistent with the magnitude and distribution of atmospheric nitrogen deposition. This anthropogenically driven increase in the N content of the upper NPO may enhance primary production in this N-limited region, potentially leading to a long-term change of the NPO from being N-limited to P-limited.

scholarly journals Fluctuating reproductive rates in Hawaii's humpback whales, Megaptera novaeangliae , reflect recent climate anomalies in the North Pacific

2019 ◽  
Vol 6 (3) ◽  
pp. 181463 ◽  
Author(s):  
R. Cartwright ◽  
A. Venema ◽  
V. Hernandez ◽  
C. Wyels ◽  
J. Cesere ◽  
...  
Keyword(s):  
Climate Change ◽  
North Pacific ◽  
Megaptera Novaeangliae ◽  
Anthropogenic Climate Change ◽  
Humpback Whales ◽  
Encounter Rates ◽  
The North ◽  
The Impact ◽  
The North Pacific ◽  
Population Segment

Alongside changing ocean temperatures and ocean chemistry, anthropogenic climate change is now impacting the fundamental processes that support marine systems. However, where natural climate aberrations mask or amplify the impacts of anthropogenic climate change, identifying key detrimental changes is challenging. In these situations, long-term, systematic field studies allow the consequences of anthropogenically driven climate change to be distinguished from the expected fluctuations in natural resources. In this study, we describe fluctuations in encounter rates for humpback whales, Megaptera novaeangliae , between 2008 and 2018. Encounter rates were assessed during transect surveys of the Au'Au Channel, Maui, Hawaii. Initially, rates increased, tracking projected growth rates for this population segment. Rates reached a peak in 2013, then declined through 2018. Specifically, between 2013 and 2018, mother–calf encounter rates dropped by 76.5%, suggesting a rapid reduction in the reproductive rate of the newly designated Hawaii Distinct Population Segment of humpback whales during this time. As this decline coincided with changes in the Pacific decadal oscillation, the development of the NE Pacific marine heat wave and the evolution of the 2016 El Niño, this may be another example of the impact of this potent trifecta of climatic events within the North Pacific.

scholarly journals Breeding seabirds increase foraging range in response to an extreme marine heatwave

2020 ◽  
Vol 646 ◽  
pp. 161-173
Author(s):  
OE Osborne ◽  
PD O’Hara ◽  
S Whelan ◽  
P Zandbergen ◽  
SA Hatch ◽  
...  
Keyword(s):  
Hot Spot ◽  
Sea Surface ◽  
Strong Impact ◽  
Rissa Tridactyla ◽  
The North ◽  
Foraging Area ◽  
Trip Distance ◽  
The North Pacific ◽  
Foraging Ranges

Marine heatwaves are increasing in frequency and can disrupt marine ecosystems non-linearly. In this study, we examined the effect of the North Pacific warming event of 2014, the largest long-term sea surface anomaly on record, on black-legged kittiwake Rissa tridactyla foraging trips before, during, and after the event. We assessed foraging trip characteristics (trip distance and duration), the dispersal of foraging locations, and the persistence of foraging areas within and among years. Foraging trip characteristics, foraging area size, and location varied from year to year. Kittiwake foraging was more dispersed, direct, and farther from the colony in years immediately after and during the warming event. A third of the foraging area used pre-heatwave (2012) was important in subsequent years, which indicates that this area was, and may still be, a perennial foraging hot spot. During the chick-rearing stage, black-legged kittiwakes increased their speed and reduced the proportion of resting compared to the incubation stage. We conclude that marine heatwaves may have a strong impact on seabird foraging, extending foraging ranges, and that those impacts may be nonlinear with a strong lag.

scholarly journals Dinámica espacio-temporal del esfuerzo en una pesquería de buceo artesanal multiespecífica y sus efectos en la variabilidad de las capturas: Implicaciones para el manejo sostenible

2014 ◽  
Vol 62 (4) ◽  
pp. 1565 ◽  
Author(s):  
Helven Naranjo Madrigal ◽  
Silvia Salas Márquez
Keyword(s):  
Fisheries Management ◽  
Pacific Coast ◽  
Temporal Dynamics ◽  
Fishing Effort ◽  
The North ◽  
Fishing Strategies ◽  
Personal Consumption ◽  
Spatial And Temporal Dynamics ◽  
The North Pacific

Artisanal diving fisheries are a source of income, employment and food security of coastal areas in many countries. Understanding the dynamics of these fisheries, including the spatial and temporal dynamics of fishing effort, gears and species can help to address the challenges involved in fisheries management. We aimed to analyze the differences in fishing strategies undertaken by fishers that use two different diving methods (hookah and free diving), and the conditions and their potential impacts on catches when adjustments to those strategies are applied over time. For this, detailed information of fishing operations from artisanal boats in the North Pacific coast of Costa Rica was analyzed in two fishing seasons (2007-2008 and 2011-2012). Data were collected by onboard observers (fishing site, fishing time, species composition, depth and visibility). Additionally, interviews with divers were applied to obtain information of price per species, species volume and fishing operations. From the total number of trips during both seasons, hookah diving was represented by a sample size of 70.5%, while free diving, with a sample of 69.5%. More than 15 species were identified in each fishing season. Nevertheless, three categories had substantial contributions in both seasons with differences in the proportions for each case: green lobster (<em>Panulirus gracilis</em>), octopus (<em>Octopus</em> sp.) and parrotfish (<em>Scarus perrico</em> and <em>S. ghobban</em>). It is worth noting that an important proportion of catch was retained by fishers for personal consumption purposes, including species of high commercial value. Additional night diving activity, increased the number of dives from one season to another. Besides, cooperation processes in free diving fishing operations, and changes in fishing effort between seasons, defined important changes in fishing strategies. Potential causes of changes in fishing strategies and the implications for management to ensure the sustainability of these fisheries in the long term are discussed.

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