Marginal coral populations: the densest known aggregation of Pocillopora in the Galápagos Archipelago is of asexual origin

Marginal coral populations: the densest known aggregation of Pocillopora in the Galápagos Archipelago is of asexual origin

[2014]

This article, written by several Living Oceans Foundation Chief Scientist, Andrew Bruckner, and Research Fellow, Joao Monteiro, along with Science Team members Illiana Baums, Joshua Feingold, and Tyler Smith, looks at the marginal coral populations of Pocillopora in the Galápagos Archipelago.

This article, written by several Living Oceans Foundation Chief Scientist, Andrew Bruckner, and Research Fellow, Joao Monteiro, along with Science Team members Illiana Baums, Joshua Feingold, and Tyler Smith, looks at the marginal coral populations of Pocillopora in the Galápagos Archipelago.

Marginal coral populations: the densest known aggregation of Pocillopora in the Galápagos Archipelago is of asexual origin

Frontiers in Marine Science
November 12, 2014
By Illiana B. Baums, Meghann Devlin-Durante, Beatrice A. A. Laing, Joshua Feingold, Tyler Smith, Andrew Bruckner, and Joao Monteiro

Coral populations at distributional margins frequently experience suboptimal and variable conditions. Recurrent El Niño-Southern Oscillation (ENSO) warming events have caused extensive mortality of reef-building corals in the Eastern Pacific, and particularly impacted branching pocilloporid corals in the Galápagos Islands. Pocillopora spp. were previously more common and formed incipient reefs at several locations in the archipelago but now occur as scattered colonies. Here, we report an unusually concentrated aggregation of colonies and evaluate their current genetic diversity. In particular we focus on a large population of 1614 live Pocillopora colonies found in a volcanic lagoon along the southern shore of Isabela Island. Forty seven colonies were sampled, primarily using a spatially explicit sampling design, and all colonies belonged to Pocillopora mitochondrial open reading frame lineage type 3a. Typing of additional Pocillopora samples (n = 40) from three other islands indicated that this stand is the only known representative of type 3a in the Galápagos Islands. The Isabela Pocillopora type 3a colonies harbored Symbiodinium ITS-2 clade C1d. Multilocus genotyping (n = 6 microsatellites) capable of resolving individual clones indicated that this stand is monogenotypic and thus the high density of colonies is a result of asexual reproduction, likely via fragmentation. Colony size distribution, while an imperfect measure, suggested the stand regrew from remnant colonies that survived the 1997/98 ENSO event but may postdate the 1982/83 ENSO. The community of Pocillopora colonies at Isabela is of particular ecological value due to its high density and support of associated organisms such as fish and benthic invertebrates. The Galapagos Pocillopora corals will continue to provide insights into the genetic structure and population dynamics of marginal coral populations.

Related Posts

Meet IFAN: Helping Bring Navigate with Care to the Next Generation

If you’ve ever seen a lighthouse flashing from the shore or a brightly colored buoy bobbing in the water, you’ve seen Aids to Navigation at work.

Aids to Navigation, often called AtoNs, help mariners navigate safely. They can mark channels, warn of hazards, help vessels determine their position, and provide other information people need to make safe decisions on the water. Around the world, these systems help guide everything from small recreational boats to large commercial or container ships.

But safe navigation isn’t only about protecting vessels and the people aboard them. The choices mariners make can also affect the animals and ecosystems beneath and around them.

That connection between maritime safety and ocean conservation is at the heart of this year’s Science Without Borders® Challenge—and of our partnership with this year’s theme sponsor, the International Foundation for Aids to Navigation (IFAN).

OceanImageBank_TheOceanAgency_Bleaching_16-scaled-1

Coral Bleaching Awareness Month: Giving Coral Reefs a Chance to Recover

For hundreds of millions of years, coral reefs have supported life in our oceans. Although they cover less than 1% of the ocean floor, they provide habitat for at least 25% of all marine species. They also support people around the world by sustaining fisheries and tourism, providing food and livelihoods, and helping protect coastlines from waves and storms.

But coral reefs are under increasing pressure. Pollution, overfishing, coastal development, physical damage, and increasingly warm ocean temperatures can all affect reef health. One of the most visible signs that a coral reef is under stress is coral bleaching.

This September, in recognition of Coral Bleaching Awareness Month, we’re taking a closer look at what happens when corals bleach, why bleaching matters, and what scientists around the world are doing to better understand, protect, and restore coral reefs.