Population dynamics of <i>Caulerpa sertularioides</i> (Chlorophyta: Bryopsidales) from Baja California, Mexico, during El Niño and La Niña years

Kang²,

2016

The Sea

Seasonal dynamics of kelp forest-forming algae, Ecklonia cava population formed following the large-scale disturbance by Typhoon 'Bolaven' in August 2012 were investigated in Jeju Island, Korea. Morphological characteristics, recruits density, mortality rate, total density and biomass were monitored bimonthly from June 2013 to June 2015. Total and longest blade lengths, and individual weight of E. cava showed distinct seasonal trends. Stipe length increased from winter to spring, but did not show increase or reduced from summer to autumn. This indicates that morphological characteristics of E. cava are mainly affected by the change of blades. The optimal temperature for E. cava growth was about 15-18°C during winter to spring while the growths were inhibited at the water temperature above 20°C during summer. E. cava exhibited very low recruitment during spring-summer. However, high recruitment was observed on April 2015 when canopy cover was very low due to low density. This indicates that recruitment of E. cava was controlled not by seasonal effects but by physical factors such as canopy and space. The mortality rate of juvenile plants was highest due to their unstable settlement. By June 2015, 34 months after the disturbances, E. cava was almost recovered to the pre-disturbance population size structure. These results suggest that recovery of kelp forest following the large-scale disturbance requires a

Section: 서 론unclassified

Recovery Pattern and Seasonal Dynamics of Kelp Species, Ecklonia cava Population Formed Following the Large-scale Disturbance

Kang²,

2016

The Sea

“…Recientemente, se ha empezado a reconocer el valor de los servicios ecológicos que los pastos marinos proporcionan al ecosistema (Costanza et al 1997), pero la demografía de las especies de algas que forman parte de las comunidades de pastos marinos, ha sido poco estudiada y se ha enfocado a las especies consideradas invasoras. Wrigth (2005) identificó diferencias entre las poblaciones nativas e invasoras de Caulerpa taxifolia, Scrosati (2001) observó que la población de Caulerpa sertularioides disminuyó en cobertura y densidad un mes antes de que ocurrieran los fenómenos del Niño y La Niña, y sugiere que el conocer la dinámica poblacional de C. sertularioides, ayudaría a entender mejor fenómenos naturales que afectan las zonas costeras, en este caso de Baja california.…”

unclassified

Demografía de Caulerpa paspaloides var. wudermannii (Bryopsidales: Caulerpaceae) en la zona costera de Campeche, México

Fuentes

Gallegos

Mandujano

2014

RBT

Demography of Caulerpa paspaloides var. wudermanni (Bryopsidales: Caulerpaceae) in the coastal zone of Campeche, México. The subaquatic vegetation of Los Petenes, Campeche, Mexico, stands out due to its considerable floristic diversity, composed of a great variety of sea grasses and several species of the genus Caulerpa sp. This is a genus of ecological relevance, with the invasive species in the Mediterranean, with negative impact on several native sub-aquatic plants; nevertheless, little is known about the demography and population dynamics of Caulerpa species and their contribution to food webs. Thus the main objective of this study was to describe the demographics of Caulerpa paspaloides var. wudermanni, using the number of stolons, complete and incomplete fronds, the diameter of the stolons and the biomass. The information was used to determine the growth rate (λ) of this species. The study was conducted in the Biosphere Reserve of Los Petenes, which is located in the Northwest of the state of Campeche. The submerged aquatic vegetation (SAV) in the Petenes Biosphere consists of monospecific and mixed populations of seagrass species (Thalassia testudinum, Halodule wrightii and Syringodium filiforme). Although chlorophytes, brown algae and red algae, are fundamental elements in the specific composition of the SAV in Petenes, several species of Caulerpa are prominent because of their coverage and abundance. In May and June of 2010, significant differences in the quantity of stolons, their diameter, incomplete and complete fronds, and the size of the stolons and rhizomes, were observed. In 2010, the finite population growth rate (λ) was 2.38±0.1571 for individuals and 1.20±0.1356 for the population, and in 2011 the values of λ were 1.80±0.3608 and 1.35±0.1571, respectively. From these results it can be concluded that the population is growing; however, growth is controlled by biotic and abiotic factors. Despite there was no apparent threat, we suggest continuing the demographic studies of C. paspaloides var. wurdemannii, as well as of other species of the same genus, not only to detect invasion or explosive growth, but also their presence indicated low oxygen levels and high sulphates. Rev. Biol. Trop. 62 (2): 729-741. Epub 2014 June 01.

“…Several studies have addressed algal populations on tropical Pacific reefs (Scrosati 2001, Carballo et al. 2002, Arthur et al.…”

mentioning

confidence: 99%

“…In comparison, studies that examine long‐term, multiyear temporal changes in algal communities seem to fall into two main categories: (1) those that examine geographic areas impacted by human activities so as to address the effects of pollution or invasive species (Krause‐Jensen et al. 2007), and (2) those that examine population trends of unimpacted areas, usually over ENSO events (Scrosati 2001, Carballo et al. 2002, Fong et al.…”

mentioning

confidence: 99%

SPATIAL AND TEMPORAL COMPARISON OF ALGAL BIODIVERSITY AND BENTHIC COVER AT GARDNER PINNACLES, NORTHWESTERN HAWAI`IAN ISLANDS¹

Vroom

Timmers

2009

Journal of Phycology

Papahānaumokuākea Marine National Monument in the Northwestern Hawai`ian Islands is the second largest marine protected area in the world, providing an opportunity for scientists to understand natural ecosystem fluctuations in subtropical marine communities with little anthropogenic impact. Gardner Pinnacles is composed of two emergent basaltic rocks and has the smallest land area of any island in the Northwestern Hawai`ian Island chain but has among the largest submerged reef area. Gardner Pinnacles is also among the least anthropogenically impacted island in the Hawai`ian Archipelago, although a thriving lobster and bottomfish industry existed in the area for many years. This study assesses nearshore algal biodiversity and percent cover at Gardner Pinnacles to examine interannual differences in community dynamics and places them in an ecosystem context by also examining associated invertebrate and fish communities. Biodiversity surveys increased the number of known eukaryotic algal species occurring in marine environments immediately adjacent to the emergent portion of Gardner Pinnacles from 31 to 77. Algal percent cover, specifically populations of the green alga Microdictyon setchellianum M. Howe, varied dramatically between sampling years, possibly in response to seasonal differences. Towed-diver surveys revealed that macroalgae covered >90% of the substrate during the 2003 sampling period but returned to 2000 levels (1%-35% cover) by 2004 without any detectable damage to other reef organisms. Fish communities remained statistically similar between sampling years, and percent cover of live coral around the island did not exceed 7%.