Marine Timbers Research Articles

Rapid Testing of Resistance of Timber to Biodegradation by Marine Wood-Boring Crustaceans.

Wood-boring invertebrates rapidly destroy marine timbers and wooden coastal infrastructure, causing billions of dollars of damage around the globe every year. As treatments of wood with broad spectrum biocides, such as creosote and chromated copper arsenate (CCA), are now restricted in marine use by legislation, naturally durable timber species and novel preservation methods of wood are required. These methods undergo testing in order to meet regulatory standards, such as the European standard for testing wood preservatives against marine borers, EN 275. Initial investigation of durable timbers species or wood preservative treatments can be achieved quickly and inexpensively through laboratory testing, which offers many advantages over marine field trials that are typically costly, long-term endeavours. Many species of Limnoria (gribble) are marine wood-boring crustaceans. Limnoria are ideal for use in laboratory testing of biodegradation of wood by marine wood-borers, due to the practicality of rearing them in aquaria and the ease of measuring their feeding rates on wood. Herein, we outline a standardizable laboratory test for assessing wood biodegradation using gribble.

Radiocarbon Wiggle-Match Dating in the Intertidal Zone

ABSTRACTRadiocarbon wiggle-match dating is a technique that can combine the versatility of radiocarbon dating with chronological information from tree-rings. This makes it useful in contexts where timbers are preserved, but dendrochronological dating is impossible. As intertidal and marine timbers are waterlogged, this can favor their preservation and hence allow wiggle-match 14C dating, which can be of significant help in deriving relatively precise chronologies for a range of coastal structures. As the technique depends on making multiple radiocarbon measurements towards a single date, efficiency in application is the key and hence a number of practical considerations need to be taken into account in advance of conducting a dating program. This paper discusses some of these practical concerns and reviews them in the context of the intertidal crannogs in the Firth of Clyde on the west coast of Scotland.

Characteristics of Attack of Coastal Timbers by Pselactus spadix (Herbst) (Col.: Curc.: Cossoninae) and an Investigation of its Life History

Summary Pselactus spadix attack of marine timbers was characterised by circular emergence holes 1.48±0.05 mm in diameter and adult tunnels (1.49±0.34 mm) breaking through the wood surface. Larval tunnels measured 0.407–1.892 mm in diameter, initiated from adult tunnels and increased in diameter away from the adult tunnel terminating in frass free pupal chambers (1.6±0.3 mm × 3.5±0.7 mm). Observations of larval tunnel locations indicated oviposition occurred inside the adult tunnels. P. spadix life history was investigated in Scots pine (Pinus sylvestris) heartwood at 22±2 °C and 99±1% r.h. Mean adult longevity was 11.5±6.5 months, with mean post-mating longevity for males (11.7±2.9 months) significantly longer than for females (6.3±1.1 months). Adults of at least 2–3 months old were found mating in galleries, which, with observations of the larval tunnel pattern, indicated P. spadix can complete its life cycle without emerging from wood. Five larval instars were identified by measurement of 1722 head capsule widths and application of Dyar's law. Mean development time from 2nd instar to adult emergence was 70.5±6.9 weeks and pupation took 14.6±5.8 days. Development from 2nd instar to reproductive adult took between 17–20 months, with life cycle approximating 24 months at 22±2 °C and 99±1%

Invertebrate biodeterioration of marine timbers above mean sea level along the coastlines of England and Wales

During 1998 and 1999, fixed structural timbers above mean sea level and driftwood along the coastline of England (South from Lancaster and Middlesborough) and Wales were surveyed for invertebrate colonisers. The cossonine Pselactus spadix was the most common coloniser, present in 63% of timbers surveyed, including hardwoods and softwoods, with moisture contents ranging from 17% to 256%, in the mid intertidal to splash zones. Microscopic examination of wood adjacent to P. spadix tunnels showed that soft rot decay was normally present, although there was no evidence of decay in 15% of the Pselactus colonised timbers. Other Coleoptera colonising timbers above mean sea level included Nacerdes melanura (13%), tunnelling softwoods in the high intertidal to splash zones and anobiids (8%), tunnelling hardwoods and softwoods above the mid intertidal zone. Limnoria spp. (Isopoda) were present in 7% of the timbers surveyed, colonising hardwoods and softwoods below the mid intertidal zone. Driftwood was colonised by marine Mollusca and Crustacea, and terrestrial Arthropoda (Coleoptera and Myriapoda). The presence of terrestrial species in 61% of the driftwood samples suggests this may be a common dispersal mechanism.

Preservation of Timber in the Tropics.

1 The nature and durability of wood.- 2 Agencies of destruction.- 3 Preservative methods.- 4 Preservative substances.- 5 Protection of logs and sawn timber.- 6 Treatment of wood by diffusion.- 7 Copper/Chrome/Arsenic wood preservatives and their application to timbers in the tropics.- 8 Preservation of marine timbers.- 9 The durability and preservation of West African timbers.- 10 Field testing of wood preservatives in tropical countries.- 11 Preservative treatment of bamboo, rubber wood and coconut palm. Simple methods for treating building timbers.- 12 Economic aspects of wood preservation.- Appendix. Safety precautions in the use of wood preservatives.- Index of subjects.

The problem of marine timber destroying organisms along the Indian coasts

The serious problem of destruction of wood in sea and brackish waters of India has been discussed with special reference to the organisms that are involved, their distribution, nature of infestation and vertical distribution, seasons of settlement, duration of larval period, growth rates and dispersal. The different ecological factors that determine the distribution of borers have been described such as temperature, salinity, primary film, rate of water flow, turbidity, pollution, effects of fouling, parasites, predators and associates. Control measures to check their ravages are also indicated.