Does global warming threaten small-scale bivalve fisheries in NW Spain?

Shellfisheries of the intertidal and shallow subtidal infaunal bivalves Ruditapes decussatus, Ruditapes philippinarum, Venerupis corrugata and Cerastoderma edule are of great socio-economic importance (in terms of landings) in Europe, specifically in the Galician Rías Baixas (NW Spain). However, ocean warming may threaten these fisheries by modifying the geographic distribution of the species and thus affecting productive areas. The present study analysed the impact of rising ocean temperature on the geographical distribution of the thermal comfort areas of these bivalves throughout the 21st century. The Delft3D model was used to downscale climate data from CORDEX and CMIP5 and was run for July and August in three future periods (2025-2049, 2050-2074 and 2075-2099) under the RCP8.5 scenario. The areas with optimal temperature conditions for shellfish harvesting located in the middle and outer parts of the rias may increase in the near future for R. decussatus, V. corrugata and C. edule and decrease in the far future for R. philippinarum. Moreover, shellfish beds located in the shallower areas of the inner parts of the Rías Baixas could be affected by increased water temperature, reducing the productive areas of the four species by the end of the century. The projected changes in thermal condition will probably lead to changes in shellfish harvesting modality (on foot or aboard vessels) with further socio-economic consequences.

Historical and future naturalization of Magallana gigas in the Galician coast in a context of climate change.

Magallana gigas is a naturalized species on the north coast of Galicia (Rías Altas, Northwest Iberian Peninsula), where it was unintentionally introduced. In recent decades, a greater abundance of M. gigas has been observed on the Galician coast, expanding towards the south, reaching the Artabro Gulf (Rías Centrales, NW Galician coast), probably due to ocean warming. Although this species has been cultivated in the Rías Baixas since the early 1990s and spawning has been reported, recruitment was never observed, which is likely due to the cold water upwelled during the spawning months. The future rise in seawater temperature may favor the naturalization of the non-indigenous species M. gigas southwards, in the Rías Baixas. Thermally, the Ría de Arousa seems to be the most favorable estuary for the future settlement of M. gigas, which may occur in the next decades. The extent of thermally favorable zones within estuaries is projected to increase rapidly by mid-century, and reaching 100 % of the estuarine area by the end of the century. As has already happened in other areas of the world, the expansion and naturalization of the Pacific oyster on the Galician coast will likely affect the native communities and economic activities, making it necessary to implement monitoring and management strategies to mitigate its effect.

Modeling salinity drop in estuarine areas under extreme precipitation events within a context of climate change: Effect on bivalve mortality in Galician Rías Baixas.

The mortality of infaunal bivalves (Venerupis corrugata, Cerastoderma edule, Ruditapes decussatus and Ruditapes philippinarum) due to a drop in salinity caused by extreme precipitation events in estuarine areas has been analyzed within a context of climate change. The Rías Baixas (NW Iberian Peninsula) were selected as a representative area of the estuarine environments where bivalve gathering is performed. Bivalve mortality under extreme precipitation events was analyzed both for historical (1990-2019) and future (2070-2099) periods. Precipitation data were retrieved from the Coordinated Regional Climate Downscaling Experiment (CORDEX) project under the Representative Concentration Pathway (RCP) 8.5 scenario and were converted into river discharges using the HEC-HMS hydrological model. The calculated river discharges were introduced into the Delft3D hydrodynamic model and simulations were performed in order to calculate transport conditions in the Rías Baixas. Salinity data were analyzed to estimate the mortality of the species due to salinity drops. In general, future conditions of moderate and severe mortality may be worse than historically observed, being more intense and covering larger areas. This is mainly observed under neap tides due to less dilution of freshwater plumes when compared with spring tides. Although all the Rías Baixas may be potentially affected, the impact will differ for each ria, being Arousa, where the highest discharges occur, the most affected. The differences among rias, especially those with a similar discharge pattern as Pontevedra and Vigo, suggest that bathymetric features also play a key role in the extent of the area affected by mortality.

The impact of climate change on the geographical distribution of habitat-forming macroalgae in the Rías Baixas.

In the current scenario of climate change characterized by a generalized warming, many species are facing local extinctions in areas with conditions near their thermal tolerance threshold. At present, the southern limit of the geographical distribution of several habitat-forming algae of cold-temperate affinities is located in the Northwest Iberian Peninsula, and the Rías Baixas may be acting as contemporary refugia at the range edge. Therefore, it is necessary to analyze future changes induced by ocean warming in this area that may induce changes in macroalgae populations. The Delft3D-Flow model forced with climatic data was used to calculate July-August sea surface temperature (SST) for the present (1999-2018) and for the far future (2080-2099). Mean daily SST was used to develop and calibrate a mechanistic geographical distribution model based on the thermal survival threshold of two intertidal habitat-forming macroalgae, namely Himanthalia elongata (L.) S.F.Gray and Bifurcaria bifurcata R. Ross. Results show that H. elongata will become extinct in the Rías Baixas by the end of the century, while B. bifurcata will persist and may occupy potential free space left by the decline in H. elongata.

How can ocean warming at the NW Iberian Peninsula affect mussel aquaculture?

Understanding and forecasting future consequences of climate change in mussel aquaculture industry require the assessment of changes in physical parameters which may affect mussel growth. The FLOW module of Delft3D model forced with climatic data was validated and calibrated for the Rías Baixas (NW Iberian Peninsula), one of the areas with the highest mussel production in the world. This model was used to perform historical (1999-2018) and future (2080-2099) projections. Temperature and stratification water conditions were compared in order to determine at what extent climate change can affect mussel production. Thermal stress will increase in a non-homogeneous throughout the water column and the comfort level of mussels will be reduced by more than 60% in the upper layers and more than 30% in deep layers in most of the mussel raft polygons. Water column stratification will increase ~ 5-10 cycles h-1 in most of the polygons reducing the vertical exchange of nutrients and oxygen. Hereby changes in water temperature and stratification at the end of the century will not be favorable for mussel growth.

A comparison of standard and novel bronchoscopic endobronchial biopsy retrieval methods.

BACKGROUND: The targets of bronchoscopic biopsy now include not only adequate tissue for histologic diagnosis but also tissue for further analysis. We prospectively compared standard and novel bronchoscopic endobronchial biopsy (EBB) retrieval methods attempting to increase tissue yield. METHODS: EBB samples were retrieved using techniques A, B, and C using a standard forceps. Method A is routinely performed conventional method, where as in method B, biopsy forceps was left protruded from the bronchoscope and in method C, both valve and forceps were removed to prevent the loss of specimen. At least 6 EBB were retrieved per patient. Results were compared with gold standard composite of confirmatory pathological or clinic-radiologic follow up. RESULTS: A total of 42 of 43 patients completed the study. The final gold standard diagnosis was cancer [non-small cell lung cancer, metastatic, carcinoid, carcinoma in situ (24)], benign disease [sarcoid, amyloid, hamartoma, and chondroid tumor (4)], and benign/nonspecific inflammation (14). EBB retrieved using standard method A were smaller than novel methods B and C (P=0.03). However, the percentage of cases where blood was the predominant component (>50%) was less by standard methods A (4/42) than B (16/42) and C (20/42) (P=0.001). There was no difference in mean viable tumor area (n=23, sensitivity for EBB for cancer 96%) between groups A compared with B and C (P 0.27) and adequacy in benign cases by subepithelial depth (>0.3 mm) (P=0.38). CONCLUSION: Standard retrieval of endobronchial biopsies through the bronchoscope and cap does not reduce the size of viable tissue and reduces contaminating blood and necrotic material.

The phosphodiesterase type IV inhibitor cilomilast decreases pro-inflammatory cytokine production from primary bronchial epithelial cells in lung transplantation patients.

BACKGROUND: Bronchiolitis obliterans syndrome (BOS) remains the major cause of long-term morbidity and mortality after lung transplantation, and new therapeutic measures are needed. We speculated that cilomilast might reduce mediators of airway inflammation and angiogenesis from the airway epithelium, supporting a potential value in the treatment of BOS. We used an ex vivo primary bronchial epithelial cell culture (PBEC) model to investigate this hypothesis. Increasing evidence suggests the epithelium is central in stimulating both inflammatory and proliferative responses in the airway. METHODS: Bronchial brushings were taken from 7 stable lung allograft recipients and were used to establish sub-confluent PBECs. The effect of incubation for 48 hours with 0.1 to 10 micromol/liter cilomilast on basal production of interleukin (IL)-8, IL-6, granulocyte macrophage colony-stimulating factor (GMCSF), and vascular endothelial growth factor (VEGF) were assayed by multiplex analyser. RESULTS: There was a dose dependent fall in basal IL-8 and GMCSF levels with cilomilast. Median change for IL-8 was -25% (range, -66% to 5%; p = 0.035) at 1 micromol/liter , and -40% (range, -72% to -20; p = 0.022) at 10 micromol/liter. Median GMSCF change was -34% (range, -70% to 16%; p = 0.05) at 1 micromol/liter, and 37% (range, -80% to -8%; p = 0.04) at 10 micromol/liter. There were no effects on VEGF. CONCLUSION: The phosphodiesterase type IV inhibitor cilomilast reduced IL-8 and GMCSF release from PBECs. These cytokines are associated with the persistence of airway neutrophilic inflammation and airway remodelling seen in obliterative bronchiolitis. These ex vivo results suggest a potential for cilomilast in the treatment of BOS, which would need to be evaluated in appropriate clinical studies.

Tuberculosis in seals caused by a novel member of the Mycobacterium tuberculosis complex: Mycobacterium pinnipedii sp. nov.

A comparison of Mycobacterium tuberculosis complex isolates from seals (pinnipeds) in Australia, Argentina, Uruguay, Great Britain and New Zealand was undertaken to determine their relationships to each other and their taxonomic position within the complex. Isolates from 30 cases of tuberculosis in six species of pinniped and seven related isolates were compared to representative and standard strains of the M. tuberculosis complex. The seal isolates could be distinguished from other members of the M. tuberculosis complex, including the recently defined 'Mycobacterium canettii' and 'Mycobacterium caprae', on the basis of host preference and phenotypic and genetic tests. Pinnipeds appear to be the natural host for this 'seal bacillus', although the organism is also pathogenic in guinea pigs, rabbits, humans, Brazilian tapir (Tapirus terrestris) and, possibly, cattle. Infection caused by the seal bacillus is predominantly associated with granulomatous lesions in the peripheral lymph nodes, lungs, pleura, spleen and peritoneum. Cases of disseminated disease have been found. As with other members of the M. tuberculosis complex, aerosols are the most likely route of transmission. The name Mycobacterium pinnipedii sp. nov. is proposed for this novel member of the M. tuberculosis complex (the type strain is 6482(T)=ATCC BAA-688(T)=NCTC 13288(T)).