Long-read sequencing (LRS) has transformed life science research by introducing third-generation sequencing (TGS) platforms applicable across various research fields, including environmental sciences. In the past decade, LRS platforms have been utilized to extensively study algal systems by improving genomic approaches such as metabarcoding, chromosome-level genome and pangenome assemblies, as well as providing new insights into algae-associated microbiomes and host–symbiont interactions. This review aims to discuss recent advancements in LRS in algal research. To achieve this aim, a systematic review was conducted according to the PRISMA 2020 guidelines and across three electronic databases (Web of Science, Scopus, and Google Scholar), with additional citation searching for relevant studies in four key algal research areas: metabarcoding, genomics, pangenomics, and host–symbionts interactions. Following the inclusion and exclusion criteria, only 51 studies were selected for this review. Throughout the review, we summarize the challenges of short-read sequencing (SRS) and discuss how LRS platforms address these challenges in algal studies. Furthermore, we discuss the future of LRS and explore how artificial intelligence (AI) can advance research on algal biology and ecology.

Harmful algal blooms (HABs) produce potent neurotoxins, such as domoic acid (DA) and saxitoxin (STX), which negatively impact marine mammal health. To contextualize these threats within specific regional ecosystems, we conducted a comprehensive meta-analysis of algal toxin concentrations in stranded and non-stranded seals and sea lions reported between 1990 and 2025. Following a systematic screening of 2377 records, 15 studies met the criteria for inclusion in our systematic review and quantitative analysis. Both toxins displayed substantial variability among studies. Notably, the concentrations of DA found in feces were markedly higher than in other matrices, and feces appears to be a high-yield matrix for detecting recent exposure. Urine and serum showed moderate DA levels, while fetal fluids were among the lowest. Geographically, most studies originated from California and the Alaskan Arctic. Multi-matrix monitoring of algal toxins is required in remote or logistically challenging regions. We propose that exposure to algal and cyanobacterial neurotoxins is a testable contributor to recurrent, unexplained mass mortality events among Caspian seals (Pusa caspica) and that targeted toxicological screening within the Caspian Sea ecosystem is urgently needed.