Improving the availability of new sources of probiotics is essential to continue implementing alternative solutions to improve coral health; one such source is urban corals. However, little is known about urban coral’s health status and whether they can harbor bacteria exhibiting probiotic traits. Here, we explored the status of the urban coral Madracis auretenra and the presence of probiotic traits in its associated culturable bacteria. After assessing ecological attributes, we observed a similar abundance (cover %) when comparing patches of M. auretenra occurring in both an urban site and a marine protected area. The urban patch also exhibited a high abundance of vibrios in coral tissues and signs of ecosystem deterioration. However, this patch showed a “good” health index condition; so, we hypothesized the presence of beneficial bacteria. We isolated 132 bacterial strains from this healthy urban M. auretenra. These bacteria were affiliated with 11 genera, including Vibrio, Shewanella, Bacillus, Exiguobacterium, Priestia, and Niallia, among others. Screenings revealed the predominant presence of potential probiotic traits such as catalase, antiQS, and the production of siderophores activities among the bacterial isolates. We proposed a list of 24 bacterial isolates as probiotic precandidates that jointly exhibited three or more of these traits, among which the Vibrio and Bacilli strains stand out. We provide insights into the health status of this urban coral and its potential as a source of bacteria exhibiting potential probiotic traits.

The monitoring of the continuous fluctuation of seawater environmental conditions plays a critical role in the management and conservation of marine and coastal ecosystems. Although previous studies in the Santa Marta region (Colombian Caribbean) have examined aspects of seawater quality, the spatiotemporal dynamics of key water quality parameters, impact gradients, and contaminant dispersion remain poorly characterized. This study presents the results of a 14-month monitoring program conducted from 2021 to 2024 at seven sampling stations: four in Santa Marta Bay and three within Tayrona National Natural Park (TNNP). These stations cover areas experiencing varying degrees of anthropogenic impact. The assessment of spatiotemporal dynamics of physicochemical seawater parameters revealed seasonal and anthropogenic influences on water quality. During the rainy periods, increased levels of turbidity, nutrients, pollutants, and oxygen demand were observed, particularly at stations impacted by wastewater discharges. Overall, these parameters exceeded the permissible limit frequency during the rainy periods, where 60% of the samples showed elevated levels of organic load. This revealed an eutrophication gradient extending from the most impacted stations to the sites located within the TNNP. Water quality index (Integrated Coastal Area Management; ICAM) assessments confirmed degraded conditions near sewage, river, and port discharge points, while TNNP stations exhibited acceptable environmental quality. These findings emphasize the protective role of marine protected areas as buffers against pollution, and highlight the need for periodic, long-term monitoring to elucidate links between water quality and ecosystem health, critical for informing conservation and management efforts in regions facing substantial anthropogenic pressures such as Santa Marta Bay and the TNNP.