Lab
Anastazia Banaszak's Lab
Institution: National Autonomous University of Mexico
Department: Institute of Ocean Sciences and Limnology
Featured research (13)
Sexual coral propagation faces a significant bottleneck due to high post‐settlement mortality, impeding large‐scale reef restoration. This study assessed the effectiveness of co‐culturing Diploria labyrinthiformis settlers with the herbivorous gastropod Cerithium lutosum and supplementing their diet with a commercially available food source, Reef‐Roids, to enhance settler survival and growth. Settlers were reared for 10 weeks under controlled conditions in one of four treatments: Control (C), Feeding with Reef‐Roids (F), Grazing by C. lutosum (G), and combined Feeding + Grazing (FG). Settlers in the Grazing treatment exhibited the highest survival at 87% after 10 weeks, significantly outperforming those in the Control (43%) and Feeding (48%) treatments. The combined feeding and grazing treatment improved survival rates to 74% and resulted in the highest growth rates, with settlers in this group averaging 11.98 ± 2.38 mm ² , approximately 3.4‐fold larger than the control and 2.6‐fold larger than the feeding group. The feeding treatment alone did not significantly enhance survival or growth, underscoring the critical role of grazing in mitigating algal competition and promoting settler development. The results highlight the efficacy of grazing by C. lutosum (G and FG) in improving both survival and growth of coral settlers, substantially surpassing the outcomes of ungrazed treatments (F and C). This study highlights the potential of integrating microherbivores, such as C. lutosum , in ex situ coral nurseries. By regulating algal growth, these grazers minimize the need for labor‐intensive maintenance, offering a scalable and cost‐effective strategy to mitigate the high mortality rates of coral settlers.
The Fourth Global Coral Bleaching Event was officially confirmed by the National Oceanic and Atmospheric Administration (NOAA) and International Coral Reef Initiative (ICRI) on April 15, 2024, with press releases and a coordinated call to arms to address the impacts of climate change (https://icriforum.org/4gbe/). As the International Coral Reef Society (ICRS), the principal association of coral reef scientists, we would be remiss not to comment on this unfortunate milestone. Given our central role in the study of coral reefs, we are compelled to join the increasing call for action against this pressing environmental challenge.
Acropora palmata is a foundational yet endangered Caribbean reef-building coral species. The lack of recovery after a disease outbreak and low recruitment has led to widespread use of fragmentation to restore populations. Another option is the production of sexual recruits (settlers) via assisted reproduction to improve the genetic diversity of depleted populations; however, the viability of this approach has not been tested over the long term. In 2011 and 2012, A. palmata larvae were cultured, settled, and the sexual recruits raised in an ex-situ nursery. Survival and growth were monitored over time. In 2014, these two F1 cohorts were moved to an in-situ nursery and after one year, a subset (29 colonies) was outplanted onto Cuevones Reef in the Mexican Caribbean. Growth and survival of these colonies were monitored periodically and compared to colonies that remained in the in-situ nursery. In 2019, samples were collected and analyzed for fertility and fecundity. 53% of the colonies were gravid and fecundity was 5.61 ± 1.91 oocytes and 3.04 ± 0.26 spermaries per polyp. A further 14 colonies from these two cohorts were outplanted in 2020 onto Picudas Reef and monitored during the subsequent spawning seasons. Two years after outplanting onto Picudas Reef, all colonies were alive and spawning of three of these colonies was recorded in 2022 in synchrony with the wild population. Gametes were collected from two colonies and crossed, with 15% fertilization success. Spermatozoa from wild colonies were then added and fertilization success increased to 95%. The resultant larvae followed normal development and symbiont uptake was visible within two weeks. The F2 generation was settled, maintained in an ex-situ nursery, and monitored for survival and growth. Both F1 and F2 generations followed a Type III survival curve with high initial mortality while in the ex-situ nursery and low later-stage mortality. The growth rates of these colonies increased three-fold after outplanting when compared to their growth rates in the ex-situ and in-situ nurseries. All colonies survived while in the in-situ nursery and for an additional nine years after outplanting onto Cuevones Reef. Overall, our results show that colonies produced by assisted breeding, once outplanted, may contribute to the genetic diversity and establishment of self-sustaining sexually-reproducing populations, which is an overarching goal of coral restoration programs.