A lesser known but emerging issue, recreational fishing debris and the anglers' opinions in South Korea.

The abundance and characteristics of marine debris originating from recreational fishing were examined across 55 sites in four different regions in Korea. The result shows that the average abundance of debris was 4.3 ± 4.2 (n/m2) in terms of the number and 13.4 ± 18.1 (g/m2) in terms of the weight, and the most often found item was fishing lines (<1 m). Detrimental fishing debris such as fishing lines, hooks and weights comprised 50.9 % of the total debris, suggesting significant impacts on wildlife. A questionnaire survey was conducted with 374 anglers across all four regions to understand their behaviors, perceptions, and preferences regarding government policies. Most of the respondents were aware of the adverse impacts of recreational fishing debris on the environment, and >50 % agreed with the introduction of recreational fishing licenses. This study highlights the urgent need to raise awareness and address the undervalued problem of recreational fishing debris.

The role of vessel wall imaging in determining the best treatment approach for coexisting aneurysms and subarachnoid hemorrhage.

PURPOSE: The purpose of this study was to investigate the utilization of gadolinium enhancement on vessel wall imaging (VWI) in treatment decision-making for patients with two intracranial aneurysms presenting as a subarachnoid hemorrhage (SAH). MATERIALS AND METHODS: We prospectively performed VWI using 3.0-Tesla (3T) magnetic resonance imaging (MRI) before treatment with endovascular coiling or surgical clipping in patients with one or two intracranial aneurysms. The VWI protocol includes three different scans: black blood (BB) T1-weighted, BB T2-weighted, TOF axial, and BB contrast-enhanced T1-weighted imaging. We analyzed all aneurysm ruptures both with and without gadolinium enhancement of the aneurysm wall. RESULTS: Thirty-eight patients with 48 aneurysms were enrolled in this study. Of these patients, 28 had a single aneurysm (15 ruptured and 13 unruptured), and 10 had two aneurysms and SAH (9 patients with two aneurysms and 1 patient with three aneurysms). Of the 15 single ruptured aneurysms, 12 (80.0%) showed positive wall enhancement, whereas 2 of the 13 single unruptured aneurysms (15.4%) demonstrated positive wall enhancement. Ten patients with SAH and two aneurysms showed wall enhancement of a single aneurysm, and these aneurysms were treated first. CONCLUSION: Gadolinium enhancement of an aneurysm wall on MRI was associated with aneurysm rupture. In patients with two aneurysms and SAH, this type of imaging can play an important role in determining the order of aneurysm treatment.

Rapid assessment of marine debris in coastal areas using a visual scoring indicator.

Information regarding the spatial distribution and standing stock of marine debris in coastal areas is a prerequisite for efficient cleanup and management. We conducted a rapid assessment of marine debris on the coasts of South Korea using a visual scoring indicator. The indicator consisted of a table and photographs representing nine pollution levels that were quantitatively tested. Locations at every 10 km were selected along the natural coastline for a total of 382 locations, and a length of 100 m at each location was assessed. Approximately 40 participants were trained and assessed the pollution levels using a smartphone application. The surveys were conducted four times in 2017, in April, June, August, and October. The total amount of marine debris stock in the natural coastal areas was estimated to be approximately 17 thousand tons. It suggests that approximately 60% of the marine debris can be cleaned from 10% of the coastline.

Abundance, composition, and distribution of microplastics larger than 20 µm in sand beaches of South Korea.

To support microplastic management, the abundance, composition, and spatial distribution of microplastics on a national scale must be known. Hence, we studied the baseline level of microplastic pollution at 20 sandy beaches along the South Korean coast. All microplastic particles extracted from the sand samples were identified down to 20 µm in size using Fourier transform infrared spectroscopy. The abundances of large microplastics (L-MPs; 1-5 mm) and small microplastics (S-MPs; 0.02-1 mm) were in the range of 0-2088 n/m2 and 1400-62800 n/m2, respectively. Maximum microplastic abundance was in the size range of 100-150 µm, and particles smaller than 300 µm accounted for 81% of the total abundance. Expanded polystyrene (EPS) accounted for 95% of L-MPs, whereas S-MPs were predominantly composed of polyethylene (49%) and polypropylene (38%). The spatial distribution of L-MPs, excluding EPS, was significantly related to population, precipitation, proximity to a river mouth and abundance of macroplastic debris on beach. However, there were no relationships between S-MPs and other environmental and source-related factors, except for macroplastic debris and L-MPs excluding EPS. These results imply that S-MPs are mainly produced on beaches by weathering, whereas L-MPs other than EPS are mainly introduced from land-based sources and are also partly produced on beaches.

Characteristics of meso-sized plastic marine debris on 20 beaches in Korea.

We surveyed the abundance and accumulation patterns of mesoplastic marine debris (5-25mm) on 20 beaches in Korea. The mean abundance of it was 13.2items/m2, and the mean weight was 1.5g/m2. Hard plastic and Styrofoam were the dominant types. The proportions of hard plastic and Styrofoam were highly variable among the beaches, each accounting for 0-100% of the total debris on a given beach with 32% and 48.5% (by number) on average, respectively. Relatively lower abundances of mesoplastic marine debris compared with our previous studies were likely due by differences of the sampling areas within the beach. The samples of this research were selected from backshore, middle line, and water edge whereas they were selected from high strandline and backshore in our previous studies. It should be considered when discussing the level of mesoplastic marine debris.

Navigational threats by derelict fishing gear to navy ships in the Korean seas.

This study assessed the impact of derelict fishing gear (DFG) on navigation. The Republic of Korea's navy (ROKN) recorded every case of approximately 170 naval ships associated with propeller entanglement by DFG from January 2010 to December 2015. The frequency of cases was 2.3 per ship and 397.7 (±37.5) per year. The amount of DFG disentangled was 0.025tons per ship and 10.0 (±1.7) tons per year. The frequency temporally decreased whereas the amount increased over these six years. To disentangle propellers, 3.1 divers were needed on average per case. Propeller entanglement occurred in all local seas and some of these areas showed increases over time. Our study highlights that the impact of DFG on navigational threats has been persistent and ubiquitous and can potentially be reduced by preventing DFG in fishing areas, with a focus on improved management by fishermen and government and with more efficient retrieval of DFG.

Arthroscopic proximal versus open subpectoral biceps tenodesis with arthroscopic repair of small- or medium-sized rotator cuff tears.

PURPOSE: The study was aimed to compare arthroscopic proximal biceps tenodesis and open subpectoral biceps tenodesis in repair of small or medium rotator cuff tears. METHODS: Eighty-five patients underwent biceps tenodesis with arthroscopic repair of a rotator cuff tear, and 66 patients were followed for median of 26.8 (18-42) months with ultrasonography were reviewed. The arthroscopic biceps tenodesis group included 34 cases, and the open subpectoral biceps group included 32 cases. Patients were evaluated using visual analogue scale (VAS), American Shoulder and Elbow Surgeons (ASES), and constant scores. Rotator cuff repair and fixation of the biceps tendon were assessed by ultrasonography. Fixation failure and degree of deformity were evaluated by the pain in the bicipital groove and biceps apex distance (BAD). RESULTS: VAS score and tenderness at the bicipital groove decreased significantly in the open subpectoral group at 3 months postoperative. In both groups, the range of motion, ASES score, and constant score increased significantly (P < 0.05). Rotator cuff retear occurred in three cases (8.8 %) in the arthroscopic group and two cases in the open subpectoral group (6.2 %). There was no significant difference in BAD between the two groups. CONCLUSION: There was no difference between open subpectoral tenodesis and arthroscopic proximal tenodesis at the time of the final follow-up; however, open subpectoral tenodesis showed encouraging results at 3-month follow-up. This early result of subpectoral tenodesis was related to removing most part of biceps tendinitis and using intra-bicipital groove tenodesis technique. LEVEL OF EVIDENCE: III.

Distribution and Size Relationships of Plastic Marine Debris on Beaches in South Korea.

The characteristics of the distribution of plastic marine debris were determined on 12 beaches in South Korea in 2013 and 2014. The abundances of large micro- (1-5 mm), meso- (5-25 mm), and macroplastics (>25 mm) were 880.4, 37.7, and 1.0 particles/m(2), respectively. Styrofoam was the most abundant debris type for large microplastics and mesoplastics (99.1 and 90.9 %, respectively). Fiber (including fabric) was the most abundant of the macroplastics (54.7 %). There were no statistical differences in the mean numbers and weights of plastic debris among three beach groups from west, south, and east coasts. No significant differences were detected between the abundances of beached plastics in high strandline and backshore for all three size groups. Spearman's rank correlation was used to determine the relationships between the three debris size classes. The abundance of large microplastics was strongly correlated with that of mesoplastics for most material types, which suggests that the contamination level of large microplastics can be estimated from that of mesoplastics. As surveying of smaller particles is more labor intensive, the surveying of mesoplastics with a 5-mm sieve is an efficient and useful way to determine "hot-spots" on beaches contaminated with large microplastics.

A comparison of microscopic and spectroscopic identification methods for analysis of microplastics in environmental samples.

The analysis of microplastics in various environmental samples requires the identification of microplastics from natural materials. The identification technique lacks a standardized protocol. Herein, stereomicroscope and Fourier transform infrared spectroscope (FT-IR) identification methods for microplastics (<1mm) were compared using the same samples from the sea surface microlayer (SML) and beach sand. Fragmented microplastics were significantly (p<0.05) underestimated and fiber was significantly overestimated using the stereomicroscope both in the SML and beach samples. The total abundance by FT-IR was higher than by microscope both in the SML and beach samples, but they were not significantly (p>0.05) different. Depending on the number of samples and the microplastic size range of interest, the appropriate identification method should be determined; selecting a suitable identification method for microplastics is crucial for evaluating microplastic pollution.

Estimation of the annual flow and stock of marine debris in South Korea for management purposes.

The annual flow and stock of marine debris in the Sea of Korea was estimated by summarizing previous survey results and integrating them with other relevant information to underpin the national marine debris management plan. The annual inflow of marine debris was estimated to be 91,195 tons [32,825 tons (36% of the total) from sources on land and 58,370 tons (64%) from ocean sources]. As of the end of 2012, the total stock of marine debris on all South Korean coasts (12,029 tons), the seabed (137,761 tons), and in the water column (2451 tons) was estimated to be 152,241 tons. In 2012, 42,595 tons of marine debris was collected from coasts, seabeds, and the water column. This is a very rare case study that estimated the amount of marine debris at a national level, the results of which provide essential information for the development of efficient marine debris management policies.

Quantities, composition, and sources of beach debris in Korea from the results of nationwide monitoring.

This study assessed the levels of marine debris pollution and identified its main sources in Korea. The surveys were bimonthly conducted by NGO leaders and volunteers on 20 beaches from March 2008 to November 2009. The quantities of marine debris were estimated at 480.9 (±267.7) count⋅100 m(-1) for number, 86.5 (±78.6) kg⋅100 m(-1) for weight, and 0.48 (±0.38) m(3)⋅100 m(-1) for volume. The level of marine debris pollution on the Korean beaches was comparable to that in the coastal areas of the North Atlantic ocean and South Africa. Plastics and styrofoam occupied the majority of debris composition in terms of number (66.7%) and volume (62.3%). The main sources of debris were fishing activities including commercial fisheries and marine aquaculture (51.3%). Especially styrofoam buoy from aquaculture was the biggest contributor to marine debris pollution on these beaches.

Estimation of lost tourism revenue in Geoje Island from the 2011 marine debris pollution event in South Korea.

Following a period of heavy rainfall in July 2011, a large amount of marine debris was washed up on the beaches of Geoje Island, South Korea, affecting the island's tourism industry. The tourism revenue decreased due to this pollution event and was estimated by multiplying the decreased number of visitors by the average expenditure of visitors to the beaches. Due to the fact that the visitor count at the Island's beaches decreased from 890,435 in 2010 to 330,207 in 2011 (i.e., a reduction of 560,228 persons, 63%), the tourism revenue loss of the island was estimated to be US$29-37 million. This study is one of the few to consider the economic effects of marine debris.

Relationships among the abundances of plastic debris in different size classes on beaches in South Korea.

Plastic debris on six beaches near the Nakdong River Estuary, South Korea, was sampled in May and September 2012 and classified into three size classes, large microplastics (1-5 mm), mesoplastics (5-25 mm), and macroplastics (>25 mm). The relationships among the abundances of the size classes were then examined. The abundances of each size category in May (before rainy season) and in September (after rainy season) were 8205 and 27,606 particles/m(2) for large microplastics, 238 and 237 particles/m(2) for mesoplastics, and 0.97 and 1.03 particles/m(2) for macroplastics, respectively. Styrofoam was the most abundant item both in microplastic and mesoplastic debris, while intact plastics were most common in macroplastic debris. The abundances of meso- and micro-plastics were the most strongly correlated. There was a higher correlation between the abundances of macro- and meso-plastics than between macro- and micro-plastics.

Impacts of marine debris on wild animals in the coastal area of Korea.

Over the last decade, marine debris has become a major factor affecting the coastal ecosystem of Korea. This study compiled information regarding how marine debris impacts wildlife in Korea. Cases of marine debris impacting wildlife were collected from experts of various fields and from local participants through an open access website from February 2010 to March 2012. A total of 21 species were affected by marine debris: 18 species of birds, 2 species of mammals, and 1 species of crustacean. Five threatened or protected species were identified: black-faced spoonbill, finless porpoise, water deer, whooper swan, and greater painted snipe. Recreational fishing gears were the types of debris that most frequently impacted wildlife, especially birds. Black tailed gulls were the most vulnerable species to recreational fishing hooks and lines. Although it was preliminary, this study revealed that recreational fishing activities should be prioritized when managing marine debris in Korea.