Bathymetric origin shapes the physiological responses of Pterygophora californica (Laminariales, Phaeophyceae) to deep marine heatwaves.
J Phycol
; 60(2): 483-502, 2024 04.
Article
em En
| MEDLINE
| ID: mdl-38264946
ABSTRACT
Kelp communities are experiencing exacerbated heat-related impacts from more intense, frequent, and deeper marine heatwaves (MHWs), imperiling the long-term survival of kelp forests in the climate change scenario. The occurrence of deep thermal anomalies is of critical importance, as elevated temperatures can impact kelp populations across their entire bathymetric range. This study evaluates the impact of MHWs on mature sporophytes of Pterygophora californica (walking kelp) from the bathymetric extremes (8-10 vs. 25-27 m) of a population situated in Baja California (Mexico). The location is near the southernmost point of the species's broad distribution (from Alaska to Mexico). The study investigated the ecophysiological responses (e.g., photobiology, nitrate uptake, oxidative stress) and growth of adult sporophytes through a two-phase experiment warming simulating a MHW and a post-MHW phase without warming. Generally, the effects of warming differed depending on the bathymetric origin of the sporophytes. The MHW facilitated essential metabolic functions of deep-water sporophytes, including photosynthesis, and promoted their growth. In contrast, shallow-water sporophytes displayed metabolic stress, reduced growth, and oxidative damage. Upon the cessation of warming, certain responses, such as a decline in nitrate uptake and net productivity, became evident in shallow-water sporophytes, implying a delay in heat-stress response. This indicates that variation in temperatures can result in more prominent effects than warming alone. The greater heat tolerance of sporophytes in deeper waters shows convincing evidence that deep portions of P. californica populations have the potential to serve as refuges from the harmful impacts of MHWs on shallow reefs.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Kelp
/
Nitratos
País/Região como assunto:
Mexico
Idioma:
En
Revista:
J Phycol
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
México
País de publicação:
Estados Unidos