No abstract

Environmental contextMicroplastics, long recognised as contaminants in aquatic ecosystems, are increasingly of environmental concern for terrestrial ecosystems. This study focuses on the potential of microplastics to act as carriers of agrochemicals and the subsequent effects on soil biota. The results indicate the need for further studies into how soil properties influence both the degradation of microplastics and their role as pollutant carriers. AbstractMicroplastics (MPs) are of environmental concern to marine ecosystems owing to the evidence of their presence in and adverse effects on organisms, but studies to address this problem on soils and its biota are scarce. Several questions can arise related to this major environmental problem and its impact on terrestrial ecosystems, mainly, whether MPs can transport contaminants (e.g. pesticides) to the soil matrix and if they can be a carrier of pesticides to soil biota. To contribute to the understanding of these issues, earthworms (Eisenia fetida) were exposed for 14 days to soil containing two different sized MPs (5mm and 0.25 µm–1mm) that were either previously sprayed or not with chlorpyrifos (CPF). Acetylcholinesterase (AChE) activity and thiobarbituric acid reactive substances (TBARS) were measured to track the exposure of the earthworms to MPs, both non-sprayed and sprayed with CPF. The behaviour of the earthworms in the test containers and the movement of MPs in the soil were assessed. The concentration of CPF in soil at the end of the experiment differed between the treatments with MPs of different sizes (17.9ngg−1 and 2442ngg−1 for large and small MPs, respectively). Despite the ability of the MPs to release CPF to the soil, the earthworms avoided the contaminated MPs at the highest contaminant level. At a lower concentration of CPF (large MPs), the earthworms avoided the MPs, but the contact time with contaminated soil was higher, as shown by the enhanced level of TBARs and AChE inhibition. However, no evidence of MPs uptake was recorded, thus it was not demonstrated that MPs can be carriers of pesticides to earthworms.

The Gulf of Guinea, in the Atlantic coast of Central Africa, has three oceanic islands that arose as part of the Cameroon Volcanic Line. From northeast to southwest these are Príncipe (139 km2), São Tomé (857 km2), and Annobón (17 km2). Although relatively close to the adjacent mainland, the islands have distinct climactic and geomorphologic characteristics, and have remained isolated throughout their geological history. Consequently, they have developed a unique biodiversity, rich in endemic species. We provide an integrated overview of the physical setting of the islands, including their geographic location, geological origin, topography, geology and soils, climate zones, and prevailing wind and ocean currents—key features that underlie the evolution of their biodiversity.

The oceanic islands of the Gulf of Guinea (Príncipe, São Tomé, and Annobón) have been the focus of biological research for over two hundred years. Following small surveys that generated modest collections in the eighteenth and early mid-nineteenth century, European institutions commissioned several exploratory missions to the region that resulted in the first major catalogues of its biodiversity. The following century brought a new wave of research investment, mostly driven by the colonial interests. After the independence of both Equatorial Guinea and São Tomé and Príncipe, novel research trends focusing on conservation aspects of biodiversity research emerged. Here we present a chronological review of the zoological and botanical expeditions to the region, commenting on their major results, collectors, and the naturalists who studied them.

Francisco Newton’s zoological expedition to Angola undertaken between 1903 and 1906 is one of the least studied of the naturalist’s life. Only three major papers regarding the herpetofauna collected in this expedition have been published, and a significant part of the specimens remains unstudied since the 1900’s. Here we review the extant herpetological specimens of this expedition, present an updated taxonomic revision, and provide new insights on their taxonomic status. The extant collection is constituted by 329 specimens (155 amphibians and 174 reptiles), corresponding to 73 species, 39 genera and 22 families, and it is presently housed in the Museu de História Natural e da Ciência da Universidade do Porto (MHNC-UP).